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// Copyright 2020 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
// This is the base::span unit test from Chromium, with small modifications.
// Modifications are noted with "Pigweed:" comments.
//
// Original file:
// https://chromium.googlesource.com/chromium/src/+/ef71f9c29f0dc6eddae474879c4ca5232ca93a6c/base/containers/span_unittest.cc
//
// In order to minimize changes from the original, this file does NOT fully
// adhere to Pigweed's style guide.
// NOLINTBEGIN(modernize-unary-static-assert)
#include "pw_span/span.h"
#include <algorithm>
#include <cstdint>
#include <memory>
#include <string>
#include <type_traits>
#include <vector>
#include "gtest/gtest.h"
#include "pw_polyfill/standard.h"
// Pigweed: gMock matchers are not yet supported.
#if 0
using ::testing::ElementsAre;
using ::testing::Eq;
using ::testing::Pointwise;
#endif // 0
namespace pw {
namespace {
// constexpr implementation of std::equal's 4 argument overload.
template <class InputIterator1, class InputIterator2>
constexpr bool constexpr_equal(InputIterator1 first1,
InputIterator1 last1,
InputIterator2 first2,
InputIterator2 last2) {
for (; first1 != last1 && first2 != last2; ++first1, ++first2) {
if (*first1 != *first2)
return false;
}
return first1 == last1 && first2 == last2;
}
} // namespace
#ifdef __cpp_deduction_guides
TEST(SpanTest, DeductionGuides_MutableArray) {
char array[] = {'a', 'b', 'c', 'd', '\0'};
auto the_span = span(array);
static_assert(the_span.extent == 5u);
static_assert(the_span.size() == 5u);
the_span[0] = '!';
EXPECT_STREQ(the_span.data(), "!bcd");
}
TEST(SpanTest, DeductionGuides_ConstArray) {
static constexpr char array[] = {'a', 'b', 'c', 'd', '\0'};
constexpr auto the_span = span(array);
static_assert(the_span.extent == 5u);
static_assert(the_span.size() == 5u);
EXPECT_STREQ(the_span.data(), "abcd");
}
TEST(SpanTest, DeductionGuides_MutableStdArray) {
std::array<char, 5> array{'a', 'b', 'c', 'd'};
auto the_span = span(array);
static_assert(the_span.extent == 5u);
static_assert(the_span.size() == 5u);
the_span[0] = '?';
EXPECT_STREQ(the_span.data(), "?bcd");
}
TEST(SpanTest, DeductionGuides_ConstStdArray) {
static constexpr std::array<char, 5> array{'a', 'b', 'c', 'd'};
constexpr auto the_span = span(array);
static_assert(the_span.extent == 5u);
static_assert(the_span.size() == 5u);
EXPECT_STREQ(the_span.data(), "abcd");
}
TEST(SpanTest, DeductionGuides_MutableContainerWithConstElements) {
std::string_view string("Hello");
auto the_span = span<const char>(string);
static_assert(the_span.extent == dynamic_extent);
EXPECT_STREQ("Hello", the_span.data());
EXPECT_EQ(5u, the_span.size());
}
TEST(SpanTest, DeductionGuides_MutableContainerWithMutableElements) {
std::string string("Hello");
auto the_span = span(string);
static_assert(the_span.extent == dynamic_extent);
EXPECT_EQ(5u, the_span.size());
the_span[1] = 'a';
EXPECT_STREQ(the_span.data(), string.data());
EXPECT_STREQ("Hallo", the_span.data());
}
#endif // __cpp_deduction_guides
class MutableStringView {
public:
using element_type = char;
using value_type = char;
using size_type = size_t;
using difference_type = ptrdiff_t;
using pointer = char*;
using reference = char&;
using iterator = char*;
using const_iterator = const char*;
using reverse_iterator = std::reverse_iterator<iterator>;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
MutableStringView(char* str) : data_(str, std::strlen(str)) {}
char& operator[](size_type index) const { return data_[index]; }
pointer data() const { return data_.data(); }
size_type size() const { return data_.size(); }
iterator begin() const { return data_.begin(); }
iterator end() const { return data_.end(); }
private:
span<char> data_;
};
#ifdef __cpp_deduction_guides
TEST(SpanTest, DeductionGuides_ConstContainerWithMutableElements) {
char data[] = "54321";
MutableStringView view(data);
auto the_span = span(view);
static_assert(the_span.extent == dynamic_extent);
EXPECT_EQ(5u, the_span.size());
view[2] = '?';
EXPECT_STREQ("54?21", the_span.data());
EXPECT_STREQ("54?21", data);
}
TEST(SpanTest, DeductionGuides_ConstContainerWithMutableValueType) {
const std::string string("Hello");
auto the_span = span(string);
static_assert(the_span.extent == dynamic_extent);
EXPECT_EQ(5u, the_span.size());
EXPECT_STREQ("Hello", the_span.data());
}
TEST(SpanTest, DeductionGuides_ConstContainerWithConstElements) {
const std::string_view string("Hello");
auto the_span = span(string);
static_assert(the_span.extent == dynamic_extent);
EXPECT_EQ(5u, the_span.size());
EXPECT_STREQ("Hello", the_span.data());
}
TEST(SpanTest, DeductionGuides_FromTemporary_ContainerWithConstElements) {
auto the_span = span(std::string_view("Hello"));
static_assert(the_span.extent == dynamic_extent);
EXPECT_EQ(5u, the_span.size());
EXPECT_STREQ("Hello", the_span.data());
}
TEST(SpanTest, DeductionGuides_FromReference) {
std::array<int, 5> array{1, 3, 5, 7, 9};
std::array<int, 5>& array_ref = array;
auto the_span = span(array_ref);
static_assert(the_span.extent == 5);
for (unsigned i = 0; i < array.size(); ++i) {
ASSERT_EQ(array[i], the_span[i]);
}
}
TEST(SpanTest, DeductionGuides_FromConstReference) {
std::string_view string = "yo!";
const std::string_view& string_ref = string;
auto the_span = span(string_ref);
static_assert(the_span.extent == dynamic_extent);
EXPECT_EQ(string, the_span.data());
}
#endif // __cpp_deduction_guides
TEST(SpanTest, DefaultConstructor) {
span<int> dynamic_span;
EXPECT_EQ(nullptr, dynamic_span.data());
EXPECT_EQ(0u, dynamic_span.size());
constexpr span<int, 0> static_span;
static_assert(nullptr == static_span.data(), "");
static_assert(static_span.empty(), "");
}
TEST(SpanTest, ConstructFromDataAndSize) {
constexpr span<int> empty_span(static_cast<int*>(nullptr), 0);
EXPECT_TRUE(empty_span.empty());
EXPECT_EQ(nullptr, empty_span.data());
std::vector<int> vector = {1, 1, 2, 3, 5, 8};
span<int> dynamic_span(vector.data(), vector.size());
EXPECT_EQ(vector.data(), dynamic_span.data());
EXPECT_EQ(vector.size(), dynamic_span.size());
for (size_t i = 0; i < dynamic_span.size(); ++i)
EXPECT_EQ(vector[i], dynamic_span[i]);
span<int, 6> static_span(vector.data(), vector.size());
EXPECT_EQ(vector.data(), static_span.data());
EXPECT_EQ(vector.size(), static_span.size());
for (size_t i = 0; i < static_span.size(); ++i)
EXPECT_EQ(vector[i], static_span[i]);
}
TEST(SpanTest, ConstructFromPointerPair) {
constexpr span<int> empty_span(static_cast<int*>(nullptr),
static_cast<int*>(nullptr));
EXPECT_TRUE(empty_span.empty());
EXPECT_EQ(nullptr, empty_span.data());
std::vector<int> vector = {1, 1, 2, 3, 5, 8};
span<int> dynamic_span(vector.data(), vector.data() + vector.size() / 2);
EXPECT_EQ(vector.data(), dynamic_span.data());
EXPECT_EQ(vector.size() / 2, dynamic_span.size());
for (size_t i = 0; i < dynamic_span.size(); ++i)
EXPECT_EQ(vector[i], dynamic_span[i]);
span<int, 3> static_span(vector.data(), vector.data() + vector.size() / 2);
EXPECT_EQ(vector.data(), static_span.data());
EXPECT_EQ(vector.size() / 2, static_span.size());
for (size_t i = 0; i < static_span.size(); ++i)
EXPECT_EQ(vector[i], static_span[i]);
}
TEST(SpanTest, AllowedConversionsFromStdArray) {
// In the following assertions we use std::is_convertible_v<From, To>, which
// for non-void types is equivalent to checking whether the following
// expression is well-formed:
//
// T obj = std::declval<From>();
//
// In particular we are checking whether From is implicitly convertible to To,
// which also implies that To is explicitly constructible from From.
static_assert(
std::is_convertible<std::array<int, 3>&, span<int>>::value,
"Error: l-value reference to std::array<int> should be convertible to "
"span<int> with dynamic extent.");
static_assert(
std::is_convertible<std::array<int, 3>&, span<int, 3>>::value,
"Error: l-value reference to std::array<int> should be convertible to "
"span<int> with the same static extent.");
static_assert(
std::is_convertible<std::array<int, 3>&, span<const int>>::value,
"Error: l-value reference to std::array<int> should be convertible to "
"span<const int> with dynamic extent.");
static_assert(
std::is_convertible<std::array<int, 3>&, span<const int, 3>>::value,
"Error: l-value reference to std::array<int> should be convertible to "
"span<const int> with the same static extent.");
static_assert(
std::is_convertible<const std::array<int, 3>&, span<const int>>::value,
"Error: const l-value reference to std::array<int> should be "
"convertible to span<const int> with dynamic extent.");
static_assert(
std::is_convertible<const std::array<int, 3>&, span<const int, 3>>::value,
"Error: const l-value reference to std::array<int> should be convertible "
"to span<const int> with the same static extent.");
static_assert(
std::is_convertible<std::array<const int, 3>&, span<const int>>::value,
"Error: l-value reference to std::array<const int> should be "
"convertible to span<const int> with dynamic extent.");
static_assert(
std::is_convertible<std::array<const int, 3>&, span<const int, 3>>::value,
"Error: l-value reference to std::array<const int> should be convertible "
"to span<const int> with the same static extent.");
static_assert(
std::is_convertible<const std::array<const int, 3>&,
span<const int>>::value,
"Error: const l-value reference to std::array<const int> should be "
"convertible to span<const int> with dynamic extent.");
static_assert(
std::is_convertible<const std::array<const int, 3>&,
span<const int, 3>>::value,
"Error: const l-value reference to std::array<const int> should be "
"convertible to span<const int> with the same static extent.");
}
TEST(SpanTest, DisallowedConstructionsFromStdArray) {
// In the following assertions we use !std::is_constructible_v<T, Args>, which
// is equivalent to checking whether the following expression is malformed:
//
// T obj(std::declval<Args>()...);
//
// In particular we are checking that T is not explicitly constructible from
// Args, which also implies that T is not implicitly constructible from Args
// as well.
static_assert(
!std::is_constructible<span<int>, const std::array<int, 3>&>::value,
"Error: span<int> with dynamic extent should not be constructible "
"from const l-value reference to std::array<int>");
static_assert(
!std::is_constructible<span<int>, std::array<const int, 3>&>::value,
"Error: span<int> with dynamic extent should not be constructible "
"from l-value reference to std::array<const int>");
static_assert(
!std::is_constructible<span<int>, const std::array<const int, 3>&>::value,
"Error: span<int> with dynamic extent should not be constructible "
"const from l-value reference to std::array<const int>");
static_assert(
!std::is_constructible<span<int, 2>, std::array<int, 3>&>::value,
"Error: span<int> with static extent should not be constructible "
"from l-value reference to std::array<int> with different extent");
static_assert(
!std::is_constructible<span<int, 4>, std::array<int, 3>&>::value,
"Error: span<int> with dynamic extent should not be constructible "
"from l-value reference to std::array<int> with different extent");
static_assert(
!std::is_constructible<span<int>, std::array<bool, 3>&>::value,
"Error: span<int> with dynamic extent should not be constructible "
"from l-value reference to std::array<bool>");
}
TEST(SpanTest, ConstructFromConstexprArray) {
static constexpr int kArray[] = {5, 4, 3, 2, 1};
constexpr span<const int> dynamic_span(kArray);
static_assert(kArray == dynamic_span.data(), "");
static_assert(std::size(kArray) == dynamic_span.size(), "");
static_assert(kArray[0] == dynamic_span[0], "");
static_assert(kArray[1] == dynamic_span[1], "");
static_assert(kArray[2] == dynamic_span[2], "");
static_assert(kArray[3] == dynamic_span[3], "");
static_assert(kArray[4] == dynamic_span[4], "");
constexpr span<const int, std::size(kArray)> static_span(kArray);
static_assert(kArray == static_span.data(), "");
static_assert(std::size(kArray) == static_span.size(), "");
static_assert(kArray[0] == static_span[0], "");
static_assert(kArray[1] == static_span[1], "");
static_assert(kArray[2] == static_span[2], "");
static_assert(kArray[3] == static_span[3], "");
static_assert(kArray[4] == static_span[4], "");
}
TEST(SpanTest, ConstructFromArray) {
int array[] = {5, 4, 3, 2, 1};
span<const int> const_span(array);
EXPECT_EQ(array, const_span.data());
EXPECT_EQ(std::size(array), const_span.size());
for (size_t i = 0; i < const_span.size(); ++i)
EXPECT_EQ(array[i], const_span[i]);
span<int> dynamic_span(array);
EXPECT_EQ(array, dynamic_span.data());
EXPECT_EQ(std::size(array), dynamic_span.size());
for (size_t i = 0; i < dynamic_span.size(); ++i)
EXPECT_EQ(array[i], dynamic_span[i]);
span<int, std::size(array)> static_span(array);
EXPECT_EQ(array, static_span.data());
EXPECT_EQ(std::size(array), static_span.size());
for (size_t i = 0; i < static_span.size(); ++i)
EXPECT_EQ(array[i], static_span[i]);
}
TEST(SpanTest, ConstructFromStdArray) {
// Note: Constructing a constexpr span from a constexpr std::array does not
// work prior to C++17 due to non-constexpr std::array::data.
std::array<int, 5> array = {{5, 4, 3, 2, 1}};
span<const int> const_span(array);
EXPECT_EQ(array.data(), const_span.data());
EXPECT_EQ(array.size(), const_span.size());
for (size_t i = 0; i < const_span.size(); ++i)
EXPECT_EQ(array[i], const_span[i]);
span<int> dynamic_span(array);
EXPECT_EQ(array.data(), dynamic_span.data());
EXPECT_EQ(array.size(), dynamic_span.size());
for (size_t i = 0; i < dynamic_span.size(); ++i)
EXPECT_EQ(array[i], dynamic_span[i]);
span<int, std::size(array)> static_span(array);
EXPECT_EQ(array.data(), static_span.data());
EXPECT_EQ(array.size(), static_span.size());
for (size_t i = 0; i < static_span.size(); ++i)
EXPECT_EQ(array[i], static_span[i]);
}
#if PW_CXX_STANDARD_IS_SUPPORTED(17)
TEST(SpanTest, ConstructFromInitializerList) {
std::initializer_list<int> il = {1, 1, 2, 3, 5, 8};
span<const int> const_span(il);
EXPECT_EQ(il.begin(), const_span.data());
EXPECT_EQ(il.size(), const_span.size());
for (size_t i = 0; i < const_span.size(); ++i)
EXPECT_EQ(il.begin()[i], const_span[i]);
span<const int, 6> static_span(il.begin(), il.end());
EXPECT_EQ(il.begin(), static_span.data());
EXPECT_EQ(il.size(), static_span.size());
for (size_t i = 0; i < static_span.size(); ++i)
EXPECT_EQ(il.begin()[i], static_span[i]);
}
TEST(SpanTest, ConstructFromStdString) {
std::string str = "foobar";
span<const char> const_span(str);
EXPECT_EQ(str.data(), const_span.data());
EXPECT_EQ(str.size(), const_span.size());
for (size_t i = 0; i < const_span.size(); ++i)
EXPECT_EQ(str[i], const_span[i]);
span<char> dynamic_span(str);
EXPECT_EQ(str.data(), dynamic_span.data());
EXPECT_EQ(str.size(), dynamic_span.size());
for (size_t i = 0; i < dynamic_span.size(); ++i)
EXPECT_EQ(str[i], dynamic_span[i]);
span<char, 6> static_span(data(str), str.size());
EXPECT_EQ(str.data(), static_span.data());
EXPECT_EQ(str.size(), static_span.size());
for (size_t i = 0; i < static_span.size(); ++i)
EXPECT_EQ(str[i], static_span[i]);
}
#endif // PW_CXX_STANDARD_IS_SUPPORTED(17)
TEST(SpanTest, ConstructFromConstContainer) {
const std::vector<int> vector = {1, 1, 2, 3, 5, 8};
span<const int> const_span(vector);
EXPECT_EQ(vector.data(), const_span.data());
EXPECT_EQ(vector.size(), const_span.size());
for (size_t i = 0; i < const_span.size(); ++i)
EXPECT_EQ(vector[i], const_span[i]);
span<const int, 6> static_span(vector.data(), vector.size());
EXPECT_EQ(vector.data(), static_span.data());
EXPECT_EQ(vector.size(), static_span.size());
for (size_t i = 0; i < static_span.size(); ++i)
EXPECT_EQ(vector[i], static_span[i]);
}
TEST(SpanTest, ConstructFromContainer) {
std::vector<int> vector = {1, 1, 2, 3, 5, 8};
span<const int> const_span(vector);
EXPECT_EQ(vector.data(), const_span.data());
EXPECT_EQ(vector.size(), const_span.size());
for (size_t i = 0; i < const_span.size(); ++i)
EXPECT_EQ(vector[i], const_span[i]);
span<int> dynamic_span(vector);
EXPECT_EQ(vector.data(), dynamic_span.data());
EXPECT_EQ(vector.size(), dynamic_span.size());
for (size_t i = 0; i < dynamic_span.size(); ++i)
EXPECT_EQ(vector[i], dynamic_span[i]);
span<int, 6> static_span(vector.data(), vector.size());
EXPECT_EQ(vector.data(), static_span.data());
EXPECT_EQ(vector.size(), static_span.size());
for (size_t i = 0; i < static_span.size(); ++i)
EXPECT_EQ(vector[i], static_span[i]);
}
#if 0
// Pigweed: gMock matchers are not yet supported.
TEST(SpanTest, ConvertNonConstIntegralToConst) {
std::vector<int> vector = {1, 1, 2, 3, 5, 8};
span<int> int_span(vector.data(), vector.size());
span<const int> const_span(int_span);
EXPECT_EQ(int_span.size(), const_span.size());
EXPECT_THAT(const_span, Pointwise(Eq(), int_span));
span<int, 6> static_int_span(vector.data(), vector.size());
span<const int, 6> static_const_span(static_int_span);
EXPECT_THAT(static_const_span, Pointwise(Eq(), static_int_span));
}
// Pigweed: gMock matchers are not yet supported.
TEST(SpanTest, ConvertNonConstPointerToConst) {
auto a = std::make_unique<int>(11);
auto b = std::make_unique<int>(22);
auto c = std::make_unique<int>(33);
std::vector<int*> vector = {a.get(), b.get(), c.get()};
span<int*> non_const_pointer_span(vector);
EXPECT_THAT(non_const_pointer_span, Pointwise(Eq(), vector));
span<int* const> const_pointer_span(non_const_pointer_span);
EXPECT_THAT(const_pointer_span, Pointwise(Eq(), non_const_pointer_span));
// Note: no test for conversion from span<int> to span<const int*>, since that
// would imply a conversion from int** to const int**, which is unsafe.
//
// Note: no test for conversion from span<int*> to span<const int* const>,
// due to CWG Defect 330:
// http://open-std.org/JTC1/SC22/WG21/docs/cwg_defects.html#330
span<int*, 3> static_non_const_pointer_span(vector.data(), vector.size());
EXPECT_THAT(static_non_const_pointer_span, Pointwise(Eq(), vector));
span<int* const, 3> static_const_pointer_span(static_non_const_pointer_span);
EXPECT_THAT(static_const_pointer_span,
Pointwise(Eq(), static_non_const_pointer_span));
}
// Pigweed: This test does not work on platforms where int32_t is long int.
TEST(SpanTest, ConvertBetweenEquivalentTypes) {
std::vector<int32_t> vector = {2, 4, 8, 16, 32};
span<int32_t> int32_t_span(vector);
span<int> converted_span(int32_t_span);
EXPECT_EQ(int32_t_span.data(), converted_span.data());
EXPECT_EQ(int32_t_span.size(), converted_span.size());
span<int32_t, 5> static_int32_t_span(vector.data(), vector.size());
span<int, 5> static_converted_span(static_int32_t_span);
EXPECT_EQ(static_int32_t_span.data(), static_converted_span.data());
EXPECT_EQ(static_int32_t_span.size(), static_converted_span.size());
}
#endif // 0
TEST(SpanTest, TemplatedFirst) {
static constexpr int array[] = {1, 2, 3};
constexpr span<const int, 3> span(array);
{
constexpr auto subspan = span.first<0>();
static_assert(span.data() == subspan.data(), "");
static_assert(subspan.empty(), "");
static_assert(0u == decltype(subspan)::extent, "");
}
{
constexpr auto subspan = span.first<1>();
static_assert(span.data() == subspan.data(), "");
static_assert(1u == subspan.size(), "");
static_assert(1u == decltype(subspan)::extent, "");
static_assert(1 == subspan[0], "");
}
{
constexpr auto subspan = span.first<2>();
static_assert(span.data() == subspan.data(), "");
static_assert(2u == subspan.size(), "");
static_assert(2u == decltype(subspan)::extent, "");
static_assert(1 == subspan[0], "");
static_assert(2 == subspan[1], "");
}
{
constexpr auto subspan = span.first<3>();
static_assert(span.data() == subspan.data(), "");
static_assert(3u == subspan.size(), "");
static_assert(3u == decltype(subspan)::extent, "");
static_assert(1 == subspan[0], "");
static_assert(2 == subspan[1], "");
static_assert(3 == subspan[2], "");
}
}
TEST(SpanTest, TemplatedLast) {
static constexpr int array[] = {1, 2, 3};
constexpr span<const int, 3> span(array);
{
constexpr auto subspan = span.last<0>();
static_assert(span.data() + 3 == subspan.data(), "");
static_assert(subspan.empty(), "");
static_assert(0u == decltype(subspan)::extent, "");
}
{
constexpr auto subspan = span.last<1>();
static_assert(span.data() + 2 == subspan.data(), "");
static_assert(1u == subspan.size(), "");
static_assert(1u == decltype(subspan)::extent, "");
static_assert(3 == subspan[0], "");
}
{
constexpr auto subspan = span.last<2>();
static_assert(span.data() + 1 == subspan.data(), "");
static_assert(2u == subspan.size(), "");
static_assert(2u == decltype(subspan)::extent, "");
static_assert(2 == subspan[0], "");
static_assert(3 == subspan[1], "");
}
{
constexpr auto subspan = span.last<3>();
static_assert(span.data() == subspan.data(), "");
static_assert(3u == subspan.size(), "");
static_assert(3u == decltype(subspan)::extent, "");
static_assert(1 == subspan[0], "");
static_assert(2 == subspan[1], "");
static_assert(3 == subspan[2], "");
}
}
TEST(SpanTest, TemplatedSubspan) {
static constexpr int array[] = {1, 2, 3};
constexpr span<const int, 3> span(array);
{
constexpr auto subspan = span.subspan<0>();
static_assert(span.data() == subspan.data(), "");
static_assert(3u == subspan.size(), "");
static_assert(3u == decltype(subspan)::extent, "");
static_assert(1 == subspan[0], "");
static_assert(2 == subspan[1], "");
static_assert(3 == subspan[2], "");
}
{
constexpr auto subspan = span.subspan<1>();
static_assert(span.data() + 1 == subspan.data(), "");
static_assert(2u == subspan.size(), "");
static_assert(2u == decltype(subspan)::extent, "");
static_assert(2 == subspan[0], "");
static_assert(3 == subspan[1], "");
}
{
constexpr auto subspan = span.subspan<2>();
static_assert(span.data() + 2 == subspan.data(), "");
static_assert(1u == subspan.size(), "");
static_assert(1u == decltype(subspan)::extent, "");
static_assert(3 == subspan[0], "");
}
{
constexpr auto subspan = span.subspan<3>();
static_assert(span.data() + 3 == subspan.data(), "");
static_assert(subspan.empty(), "");
static_assert(0u == decltype(subspan)::extent, "");
}
{
constexpr auto subspan = span.subspan<0, 0>();
static_assert(span.data() == subspan.data(), "");
static_assert(subspan.empty(), "");
static_assert(0u == decltype(subspan)::extent, "");
}
{
constexpr auto subspan = span.subspan<1, 0>();
static_assert(span.data() + 1 == subspan.data(), "");
static_assert(subspan.empty(), "");
static_assert(0u == decltype(subspan)::extent, "");
}
{
constexpr auto subspan = span.subspan<2, 0>();
static_assert(span.data() + 2 == subspan.data(), "");
static_assert(subspan.empty(), "");
static_assert(0u == decltype(subspan)::extent, "");
}
{
constexpr auto subspan = span.subspan<0, 1>();
static_assert(span.data() == subspan.data(), "");
static_assert(1u == subspan.size(), "");
static_assert(1u == decltype(subspan)::extent, "");
static_assert(1 == subspan[0], "");
}
{
constexpr auto subspan = span.subspan<1, 1>();
static_assert(span.data() + 1 == subspan.data(), "");
static_assert(1u == subspan.size(), "");
static_assert(1u == decltype(subspan)::extent, "");
static_assert(2 == subspan[0], "");
}
{
constexpr auto subspan = span.subspan<2, 1>();
static_assert(span.data() + 2 == subspan.data(), "");
static_assert(1u == subspan.size(), "");
static_assert(1u == decltype(subspan)::extent, "");
static_assert(3 == subspan[0], "");
}
{
constexpr auto subspan = span.subspan<0, 2>();
static_assert(span.data() == subspan.data(), "");
static_assert(2u == subspan.size(), "");
static_assert(2u == decltype(subspan)::extent, "");
static_assert(1 == subspan[0], "");
static_assert(2 == subspan[1], "");
}
{
constexpr auto subspan = span.subspan<1, 2>();
static_assert(span.data() + 1 == subspan.data(), "");
static_assert(2u == subspan.size(), "");
static_assert(2u == decltype(subspan)::extent, "");
static_assert(2 == subspan[0], "");
static_assert(3 == subspan[1], "");
}
{
constexpr auto subspan = span.subspan<0, 3>();
static_assert(span.data() == subspan.data(), "");
static_assert(3u == subspan.size(), "");
static_assert(3u == decltype(subspan)::extent, "");
static_assert(1 == subspan[0], "");
static_assert(2 == subspan[1], "");
static_assert(3 == subspan[2], "");
}
}
TEST(SpanTest, SubscriptedBeginIterator) {
int array[] = {1, 2, 3};
span<const int> const_span(array);
for (size_t i = 0; i < const_span.size(); ++i)
EXPECT_EQ(array[i], const_span.begin()[i]);
span<int> mutable_span(array);
for (size_t i = 0; i < mutable_span.size(); ++i)
EXPECT_EQ(array[i], mutable_span.begin()[i]);
}
TEST(SpanTest, TemplatedFirstOnDynamicSpan) {
int array[] = {1, 2, 3};
span<const int> span(array);
{
auto subspan = span.first<0>();
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(0u, subspan.size());
static_assert(0u == decltype(subspan)::extent, "");
}
{
auto subspan = span.first<1>();
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(1u, subspan.size());
static_assert(1u == decltype(subspan)::extent, "");
EXPECT_EQ(1, subspan[0]);
}
{
auto subspan = span.first<2>();
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(2u, subspan.size());
static_assert(2u == decltype(subspan)::extent, "");
EXPECT_EQ(1, subspan[0]);
EXPECT_EQ(2, subspan[1]);
}
{
auto subspan = span.first<3>();
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(3u, subspan.size());
static_assert(3u == decltype(subspan)::extent, "");
EXPECT_EQ(1, subspan[0]);
EXPECT_EQ(2, subspan[1]);
EXPECT_EQ(3, subspan[2]);
}
}
TEST(SpanTest, TemplatedLastOnDynamicSpan) {
int array[] = {1, 2, 3};
span<int> span(array);
{
auto subspan = span.last<0>();
EXPECT_EQ(span.data() + 3, subspan.data());
EXPECT_EQ(0u, subspan.size());
static_assert(0u == decltype(subspan)::extent, "");
}
{
auto subspan = span.last<1>();
EXPECT_EQ(span.data() + 2, subspan.data());
EXPECT_EQ(1u, subspan.size());
static_assert(1u == decltype(subspan)::extent, "");
EXPECT_EQ(3, subspan[0]);
}
{
auto subspan = span.last<2>();
EXPECT_EQ(span.data() + 1, subspan.data());
EXPECT_EQ(2u, subspan.size());
static_assert(2u == decltype(subspan)::extent, "");
EXPECT_EQ(2, subspan[0]);
EXPECT_EQ(3, subspan[1]);
}
{
auto subspan = span.last<3>();
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(3u, subspan.size());
static_assert(3u == decltype(subspan)::extent, "");
EXPECT_EQ(1, subspan[0]);
EXPECT_EQ(2, subspan[1]);
EXPECT_EQ(3, subspan[2]);
}
}
TEST(SpanTest, TemplatedSubspanFromDynamicSpan) {
int array[] = {1, 2, 3};
span<int, 3> span(array);
{
auto subspan = span.subspan<0>();
EXPECT_EQ(span.data(), subspan.data());
static_assert(3u == decltype(subspan)::extent, "");
EXPECT_EQ(3u, subspan.size());
EXPECT_EQ(1, subspan[0]);
EXPECT_EQ(2, subspan[1]);
EXPECT_EQ(3, subspan[2]);
}
{
auto subspan = span.subspan<1>();
EXPECT_EQ(span.data() + 1, subspan.data());
EXPECT_EQ(2u, subspan.size());
static_assert(2u == decltype(subspan)::extent, "");
EXPECT_EQ(2, subspan[0]);
EXPECT_EQ(3, subspan[1]);
}
{
auto subspan = span.subspan<2>();
EXPECT_EQ(span.data() + 2, subspan.data());
EXPECT_EQ(1u, subspan.size());
static_assert(1u == decltype(subspan)::extent, "");
EXPECT_EQ(3, subspan[0]);
}
{
auto subspan = span.subspan<3>();
EXPECT_EQ(span.data() + 3, subspan.data());
EXPECT_EQ(0u, subspan.size());
static_assert(0u == decltype(subspan)::extent, "");
}
{
auto subspan = span.subspan<0, 0>();
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(0u, subspan.size());
static_assert(0u == decltype(subspan)::extent, "");
}
{
auto subspan = span.subspan<1, 0>();
EXPECT_EQ(span.data() + 1, subspan.data());
EXPECT_EQ(0u, subspan.size());
static_assert(0u == decltype(subspan)::extent, "");
}
{
auto subspan = span.subspan<2, 0>();
EXPECT_EQ(span.data() + 2, subspan.data());
EXPECT_EQ(0u, subspan.size());
static_assert(0u == decltype(subspan)::extent, "");
}
{
auto subspan = span.subspan<0, 1>();
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(1u, subspan.size());
static_assert(1u == decltype(subspan)::extent, "");
EXPECT_EQ(1, subspan[0]);
}
{
auto subspan = span.subspan<1, 1>();
EXPECT_EQ(span.data() + 1, subspan.data());
EXPECT_EQ(1u, subspan.size());
static_assert(1u == decltype(subspan)::extent, "");
EXPECT_EQ(2, subspan[0]);
}
{
auto subspan = span.subspan<2, 1>();
EXPECT_EQ(span.data() + 2, subspan.data());
EXPECT_EQ(1u, subspan.size());
static_assert(1u == decltype(subspan)::extent, "");
EXPECT_EQ(3, subspan[0]);
}
{
auto subspan = span.subspan<0, 2>();
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(2u, subspan.size());
static_assert(2u == decltype(subspan)::extent, "");
EXPECT_EQ(1, subspan[0]);
EXPECT_EQ(2, subspan[1]);
}
{
auto subspan = span.subspan<1, 2>();
EXPECT_EQ(span.data() + 1, subspan.data());
EXPECT_EQ(2u, subspan.size());
static_assert(2u == decltype(subspan)::extent, "");
EXPECT_EQ(2, subspan[0]);
EXPECT_EQ(3, subspan[1]);
}
{
auto subspan = span.subspan<0, 3>();
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(3u, subspan.size());
static_assert(3u == decltype(subspan)::extent, "");
EXPECT_EQ(1, subspan[0]);
EXPECT_EQ(2, subspan[1]);
EXPECT_EQ(3, subspan[2]);
}
}
TEST(SpanTest, First) {
int array[] = {1, 2, 3};
span<int> span(array);
{
auto subspan = span.first(0);
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(0u, subspan.size());
}
{
auto subspan = span.first(1);
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(1u, subspan.size());
EXPECT_EQ(1, subspan[0]);
}
{
auto subspan = span.first(2);
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(2u, subspan.size());
EXPECT_EQ(1, subspan[0]);
EXPECT_EQ(2, subspan[1]);
}
{
auto subspan = span.first(3);
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(3u, subspan.size());
EXPECT_EQ(1, subspan[0]);
EXPECT_EQ(2, subspan[1]);
EXPECT_EQ(3, subspan[2]);
}
}
TEST(SpanTest, Last) {
int array[] = {1, 2, 3};
span<int> span(array);
{
auto subspan = span.last(0);
EXPECT_EQ(span.data() + 3, subspan.data());
EXPECT_EQ(0u, subspan.size());
}
{
auto subspan = span.last(1);
EXPECT_EQ(span.data() + 2, subspan.data());
EXPECT_EQ(1u, subspan.size());
EXPECT_EQ(3, subspan[0]);
}
{
auto subspan = span.last(2);
EXPECT_EQ(span.data() + 1, subspan.data());
EXPECT_EQ(2u, subspan.size());
EXPECT_EQ(2, subspan[0]);
EXPECT_EQ(3, subspan[1]);
}
{
auto subspan = span.last(3);
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(3u, subspan.size());
EXPECT_EQ(1, subspan[0]);
EXPECT_EQ(2, subspan[1]);
EXPECT_EQ(3, subspan[2]);
}
}
TEST(SpanTest, Subspan) {
int array[] = {1, 2, 3};
span<int> span(array);
{
auto subspan = span.subspan(0);
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(3u, subspan.size());
EXPECT_EQ(1, subspan[0]);
EXPECT_EQ(2, subspan[1]);
EXPECT_EQ(3, subspan[2]);
}
{
auto subspan = span.subspan(1);
EXPECT_EQ(span.data() + 1, subspan.data());
EXPECT_EQ(2u, subspan.size());
EXPECT_EQ(2, subspan[0]);
EXPECT_EQ(3, subspan[1]);
}
{
auto subspan = span.subspan(2);
EXPECT_EQ(span.data() + 2, subspan.data());
EXPECT_EQ(1u, subspan.size());
EXPECT_EQ(3, subspan[0]);
}
{
auto subspan = span.subspan(3);
EXPECT_EQ(span.data() + 3, subspan.data());
EXPECT_EQ(0u, subspan.size());
}
{
auto subspan = span.subspan(0, 0);
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(0u, subspan.size());
}
{
auto subspan = span.subspan(1, 0);
EXPECT_EQ(span.data() + 1, subspan.data());
EXPECT_EQ(0u, subspan.size());
}
{
auto subspan = span.subspan(2, 0);
EXPECT_EQ(span.data() + 2, subspan.data());
EXPECT_EQ(0u, subspan.size());
}
{
auto subspan = span.subspan(0, 1);
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(1u, subspan.size());
EXPECT_EQ(1, subspan[0]);
}
{
auto subspan = span.subspan(1, 1);
EXPECT_EQ(span.data() + 1, subspan.data());
EXPECT_EQ(1u, subspan.size());
EXPECT_EQ(2, subspan[0]);
}
{
auto subspan = span.subspan(2, 1);
EXPECT_EQ(span.data() + 2, subspan.data());
EXPECT_EQ(1u, subspan.size());
EXPECT_EQ(3, subspan[0]);
}
{
auto subspan = span.subspan(0, 2);
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(2u, subspan.size());
EXPECT_EQ(1, subspan[0]);
EXPECT_EQ(2, subspan[1]);
}
{
auto subspan = span.subspan(1, 2);
EXPECT_EQ(span.data() + 1, subspan.data());
EXPECT_EQ(2u, subspan.size());
EXPECT_EQ(2, subspan[0]);
EXPECT_EQ(3, subspan[1]);
}
{
auto subspan = span.subspan(0, 3);
EXPECT_EQ(span.data(), subspan.data());
EXPECT_EQ(span.size(), subspan.size());
EXPECT_EQ(1, subspan[0]);
EXPECT_EQ(2, subspan[1]);
EXPECT_EQ(3, subspan[2]);
}
}
TEST(SpanTest, Size) {
{
span<int> span;
EXPECT_EQ(0u, span.size());
}
{
int array[] = {1, 2, 3};
span<int> span(array);
EXPECT_EQ(3u, span.size());
}
}
TEST(SpanTest, SizeBytes) {
{
span<int> span;
EXPECT_EQ(0u, span.size_bytes());
}
{
int array[] = {1, 2, 3};
span<int> span(array);
EXPECT_EQ(3u * sizeof(int), span.size_bytes());
}
}
TEST(SpanTest, Empty) {
{
span<int> span;
EXPECT_TRUE(span.empty());
}
{
int array[] = {1, 2, 3};
span<int> span(array);
EXPECT_FALSE(span.empty());
}
}
TEST(SpanTest, OperatorAt) {
static constexpr int kArray[] = {1, 6, 1, 8, 0};
constexpr span<const int> span(kArray);
static_assert(&kArray[0] == &span[0],
"span[0] does not refer to the same element as kArray[0]");
static_assert(&kArray[1] == &span[1],
"span[1] does not refer to the same element as kArray[1]");
static_assert(&kArray[2] == &span[2],
"span[2] does not refer to the same element as kArray[2]");
static_assert(&kArray[3] == &span[3],
"span[3] does not refer to the same element as kArray[3]");
static_assert(&kArray[4] == &span[4],
"span[4] does not refer to the same element as kArray[4]");
}
TEST(SpanTest, Front) {
static constexpr int kArray[] = {1, 6, 1, 8, 0};
constexpr span<const int> span(kArray);
static_assert(&kArray[0] == &span.front(),
"span.front() does not refer to the same element as kArray[0]");
}
TEST(SpanTest, Back) {
static constexpr int kArray[] = {1, 6, 1, 8, 0};
constexpr span<const int> span(kArray);
static_assert(&kArray[4] == &span.back(),
"span.back() does not refer to the same element as kArray[4]");
}
// Pigweed: This test uses gMock features not yet supported in Pigweed.
#if 0
TEST(SpanTest, Iterator) {
static constexpr int kArray[] = {1, 6, 1, 8, 0};
constexpr span<const int> span(kArray);
std::vector<int> results;
for (int i : span)
results.emplace_back(i);
EXPECT_THAT(results, ElementsAre(1, 6, 1, 8, 0));
}
#endif // 0
TEST(SpanTest, ConstexprIterator) {
static constexpr int kArray[] = {1, 6, 1, 8, 0};
constexpr span<const int> span(kArray);
static_assert(
constexpr_equal(
std::begin(kArray), std::end(kArray), span.begin(), span.end()),
"");
static_assert(1 == span.begin()[0], "");
// Pigweed: These tests assume an iterator object, but Pigweed's span uses a
// simple pointer.
#if 0
static_assert(1 == *(span.begin() += 0), "");
static_assert(6 == *(span.begin() += 1), "");
static_assert(1 == *((span.begin() + 1) -= 1), "");
static_assert(6 == *((span.begin() + 1) -= 0), "");
#endif // 0
}
TEST(SpanTest, ReverseIterator) {
static constexpr int kArray[] = {1, 6, 1, 8, 0};
constexpr span<const int> span(kArray);
EXPECT_TRUE(std::equal(
std::rbegin(kArray), std::rend(kArray), span.rbegin(), span.rend()));
EXPECT_TRUE(std::equal(std::crbegin(kArray),
std::crend(kArray),
std::crbegin(span),
std::crend(span)));
}
// Pigweed: These are tests for make_span, which is not included in Pigweed's
// implementation, since class template deduction is available.
#if 0
TEST(SpanTest, AsBytes) {
{
constexpr int kArray[] = {2, 3, 5, 7, 11, 13};
span<const uint8_t, sizeof(kArray)> bytes_span =
as_bytes(make_span(kArray));
EXPECT_EQ(reinterpret_cast<const uint8_t*>(kArray), bytes_span.data());
EXPECT_EQ(sizeof(kArray), bytes_span.size());
EXPECT_EQ(bytes_span.size(), bytes_span.size_bytes());
}
{
std::vector<int> vec = {1, 1, 2, 3, 5, 8};
span<int> mutable_span(vec);
span<const uint8_t> bytes_span = as_bytes(mutable_span);
EXPECT_EQ(reinterpret_cast<const uint8_t*>(vec.data()), bytes_span.data());
EXPECT_EQ(sizeof(int) * vec.size(), bytes_span.size());
EXPECT_EQ(bytes_span.size(), bytes_span.size_bytes());
}
}
TEST(SpanTest, AsWritableBytes) {
std::vector<int> vec = {1, 1, 2, 3, 5, 8};
span<int> mutable_span(vec);
span<uint8_t> writable_bytes_span = as_writable_bytes(mutable_span);
EXPECT_EQ(reinterpret_cast<uint8_t*>(vec.data()), writable_bytes_span.data());
EXPECT_EQ(sizeof(int) * vec.size(), writable_bytes_span.size());
EXPECT_EQ(writable_bytes_span.size(), writable_bytes_span.size_bytes());
// Set the first entry of vec to zero while writing through the span.
std::fill(writable_bytes_span.data(),
writable_bytes_span.data() + sizeof(int), 0);
EXPECT_EQ(0, vec[0]);
}
TEST(SpanTest, MakeSpanFromDataAndSize) {
int* nullint = nullptr;
auto empty_span = make_span(nullint, 0);
EXPECT_TRUE(empty_span.empty());
EXPECT_EQ(nullptr, empty_span.data());
std::vector<int> vector = {1, 1, 2, 3, 5, 8};
span<int> expected_span(vector.data(), vector.size());
auto made_span = make_span(vector.data(), vector.size());
EXPECT_EQ(expected_span.data(), made_span.data());
EXPECT_EQ(expected_span.size(), made_span.size());
static_assert(decltype(made_span)::extent == dynamic_extent, "");
static_assert(
std::is_same<decltype(expected_span), decltype(made_span)>::value,
"the type of made_span differs from expected_span!");
}
TEST(SpanTest, MakeSpanFromPointerPair) {
int* nullint = nullptr;
auto empty_span = make_span(nullint, nullint);
EXPECT_TRUE(empty_span.empty());
EXPECT_EQ(nullptr, empty_span.data());
std::vector<int> vector = {1, 1, 2, 3, 5, 8};
span<int> expected_span(vector.data(), vector.size());
auto made_span = make_span(vector.data(), vector.data() + vector.size());
EXPECT_EQ(expected_span.data(), made_span.data());
EXPECT_EQ(expected_span.size(), made_span.size());
static_assert(decltype(made_span)::extent == dynamic_extent, "");
static_assert(
std::is_same<decltype(expected_span), decltype(made_span)>::value,
"the type of made_span differs from expected_span!");
}
TEST(SpanTest, MakeSpanFromConstexprArray) {
static constexpr int kArray[] = {1, 2, 3, 4, 5};
constexpr span<const int, 5> expected_span(kArray);
constexpr auto made_span = make_span(kArray);
EXPECT_EQ(expected_span.data(), made_span.data());
EXPECT_EQ(expected_span.size(), made_span.size());
static_assert(decltype(made_span)::extent == 5, "");
static_assert(
std::is_same<decltype(expected_span), decltype(made_span)>::value,
"the type of made_span differs from expected_span!");
}
TEST(SpanTest, MakeSpanFromStdArray) {
const std::array<int, 5> kArray = {{1, 2, 3, 4, 5}};
span<const int, 5> expected_span(kArray);
auto made_span = make_span(kArray);
EXPECT_EQ(expected_span.data(), made_span.data());
EXPECT_EQ(expected_span.size(), made_span.size());
static_assert(decltype(made_span)::extent == 5, "");
static_assert(
std::is_same<decltype(expected_span), decltype(made_span)>::value,
"the type of made_span differs from expected_span!");
}
TEST(SpanTest, MakeSpanFromConstContainer) {
const std::vector<int> vector = {-1, -2, -3, -4, -5};
span<const int> expected_span(vector);
auto made_span = make_span(vector);
EXPECT_EQ(expected_span.data(), made_span.data());
EXPECT_EQ(expected_span.size(), made_span.size());
static_assert(decltype(made_span)::extent == dynamic_extent, "");
static_assert(
std::is_same<decltype(expected_span), decltype(made_span)>::value,
"the type of made_span differs from expected_span!");
}
TEST(SpanTest, MakeStaticSpanFromConstContainer) {
const std::vector<int> vector = {-1, -2, -3, -4, -5};
span<const int, 5> expected_span(vector.data(), vector.size());
auto made_span = make_span<5>(vector);
EXPECT_EQ(expected_span.data(), made_span.data());
EXPECT_EQ(expected_span.size(), made_span.size());
static_assert(decltype(made_span)::extent == 5, "");
static_assert(
std::is_same<decltype(expected_span), decltype(made_span)>::value,
"the type of made_span differs from expected_span!");
}
TEST(SpanTest, MakeSpanFromContainer) {
std::vector<int> vector = {-1, -2, -3, -4, -5};
span<int> expected_span(vector);
auto made_span = make_span(vector);
EXPECT_EQ(expected_span.data(), made_span.data());
EXPECT_EQ(expected_span.size(), made_span.size());
static_assert(decltype(made_span)::extent == dynamic_extent, "");
static_assert(
std::is_same<decltype(expected_span), decltype(made_span)>::value,
"the type of made_span differs from expected_span!");
}
TEST(SpanTest, MakeStaticSpanFromContainer) {
std::vector<int> vector = {-1, -2, -3, -4, -5};
span<int, 5> expected_span(vector.data(), vector.size());
auto made_span = make_span<5>(vector);
EXPECT_EQ(expected_span.data(), make_span<5>(vector).data());
EXPECT_EQ(expected_span.size(), make_span<5>(vector).size());
static_assert(decltype(make_span<5>(vector))::extent == 5, "");
static_assert(
std::is_same<decltype(expected_span), decltype(made_span)>::value,
"the type of made_span differs from expected_span!");
}
TEST(SpanTest, MakeStaticSpanFromConstexprContainer) {
constexpr StringPiece str = "Hello, World";
constexpr auto made_span = make_span<12>(str);
static_assert(str.data() == made_span.data(), "Error: data() does not match");
static_assert(str.size() == made_span.size(), "Error: size() does not match");
static_assert(std::is_same<decltype(str)::value_type,
decltype(made_span)::value_type>::value,
"Error: value_type does not match");
static_assert(str.size() == decltype(made_span)::extent,
"Error: extent does not match");
}
TEST(SpanTest, MakeSpanFromRValueContainer) {
std::vector<int> vector = {-1, -2, -3, -4, -5};
span<const int> expected_span(vector);
// Note: While static_cast<T&&>(foo) is effectively just a fancy spelling of
// std::move(foo), make_span does not actually take ownership of the passed in
// container. Writing it this way makes it more obvious that we simply care
// about the right behavour when passing rvalues.
auto made_span = make_span(static_cast<std::vector<int>&&>(vector));
EXPECT_EQ(expected_span.data(), made_span.data());
EXPECT_EQ(expected_span.size(), made_span.size());
static_assert(decltype(made_span)::extent == dynamic_extent, "");
static_assert(
std::is_same<decltype(expected_span), decltype(made_span)>::value,
"the type of made_span differs from expected_span!");
}
TEST(SpanTest, MakeStaticSpanFromRValueContainer) {
std::vector<int> vector = {-1, -2, -3, -4, -5};
span<const int, 5> expected_span(vector.data(), vector.size());
// Note: While static_cast<T&&>(foo) is effectively just a fancy spelling of
// std::move(foo), make_span does not actually take ownership of the passed in
// container. Writing it this way makes it more obvious that we simply care
// about the right behavour when passing rvalues.
auto made_span = make_span<5>(static_cast<std::vector<int>&&>(vector));
EXPECT_EQ(expected_span.data(), made_span.data());
EXPECT_EQ(expected_span.size(), made_span.size());
static_assert(decltype(made_span)::extent == 5, "");
static_assert(
std::is_same<decltype(expected_span), decltype(made_span)>::value,
"the type of made_span differs from expected_span!");
}
TEST(SpanTest, MakeSpanFromDynamicSpan) {
static constexpr int kArray[] = {1, 2, 3, 4, 5};
constexpr span<const int> expected_span(kArray);
constexpr auto made_span = make_span(expected_span);
static_assert(std::is_same<decltype(expected_span)::element_type,
decltype(made_span)::element_type>::value,
"make_span(span) should have the same element_type as span");
static_assert(expected_span.data() == made_span.data(),
"make_span(span) should have the same data() as span");
static_assert(expected_span.size() == made_span.size(),
"make_span(span) should have the same size() as span");
static_assert(decltype(made_span)::extent == decltype(expected_span)::extent,
"make_span(span) should have the same extent as span");
static_assert(
std::is_same<decltype(expected_span), decltype(made_span)>::value,
"the type of made_span differs from expected_span!");
}
TEST(SpanTest, MakeSpanFromStaticSpan) {
static constexpr int kArray[] = {1, 2, 3, 4, 5};
constexpr span<const int, 5> expected_span(kArray);
constexpr auto made_span = make_span(expected_span);
static_assert(std::is_same<decltype(expected_span)::element_type,
decltype(made_span)::element_type>::value,
"make_span(span) should have the same element_type as span");
static_assert(expected_span.data() == made_span.data(),
"make_span(span) should have the same data() as span");
static_assert(expected_span.size() == made_span.size(),
"make_span(span) should have the same size() as span");
static_assert(decltype(made_span)::extent == decltype(expected_span)::extent,
"make_span(span) should have the same extent as span");
static_assert(
std::is_same<decltype(expected_span), decltype(made_span)>::value,
"the type of made_span differs from expected_span!");
}
#endif // 0
TEST(SpanTest, EnsureConstexprGoodness) {
static constexpr int kArray[] = {5, 4, 3, 2, 1};
constexpr span<const int> constexpr_span(kArray);
const size_t size = 2;
const size_t start = 1;
constexpr span<const int> subspan =
constexpr_span.subspan(start, start + size);
for (size_t i = 0; i < subspan.size(); ++i)
EXPECT_EQ(kArray[start + i], subspan[i]);
constexpr span<const int> firsts = constexpr_span.first(size);
for (size_t i = 0; i < firsts.size(); ++i)
EXPECT_EQ(kArray[i], firsts[i]);
constexpr span<const int> lasts = constexpr_span.last(size);
for (size_t i = 0; i < lasts.size(); ++i) {
const size_t j = (std::size(kArray) - size) + i;
EXPECT_EQ(kArray[j], lasts[i]);
}
constexpr int item = constexpr_span[size];
EXPECT_EQ(kArray[size], item);
}
#if 0
// Pigweed: Death tests are not yet supported.
TEST(SpanTest, OutOfBoundsDeath) {
constexpr span<int, 0> kEmptySpan;
ASSERT_DEATH_IF_SUPPORTED(kEmptySpan[0], "");
ASSERT_DEATH_IF_SUPPORTED(kEmptySpan.first(1), "");
ASSERT_DEATH_IF_SUPPORTED(kEmptySpan.last(1), "");
ASSERT_DEATH_IF_SUPPORTED(kEmptySpan.subspan(1), "");
constexpr span<int> kEmptyDynamicSpan;
ASSERT_DEATH_IF_SUPPORTED(kEmptyDynamicSpan[0], "");
ASSERT_DEATH_IF_SUPPORTED(kEmptyDynamicSpan.front(), "");
ASSERT_DEATH_IF_SUPPORTED(kEmptyDynamicSpan.first(1), "");
ASSERT_DEATH_IF_SUPPORTED(kEmptyDynamicSpan.last(1), "");
ASSERT_DEATH_IF_SUPPORTED(kEmptyDynamicSpan.back(), "");
ASSERT_DEATH_IF_SUPPORTED(kEmptyDynamicSpan.subspan(1), "");
static constexpr int kArray[] = {0, 1, 2};
constexpr span<const int> kNonEmptyDynamicSpan(kArray);
EXPECT_EQ(3U, kNonEmptyDynamicSpan.size());
ASSERT_DEATH_IF_SUPPORTED(kNonEmptyDynamicSpan[4], "");
ASSERT_DEATH_IF_SUPPORTED(kNonEmptyDynamicSpan.subspan(10), "");
ASSERT_DEATH_IF_SUPPORTED(kNonEmptyDynamicSpan.subspan(1, 7), "");
}
// Pigweed: These tests use CheckedContiguousConstIterator, which isn't used in
// Pigweed's version.
TEST(SpanTest, IteratorIsRangeMoveSafe) {
static constexpr int kArray[] = {1, 6, 1, 8, 0};
const size_t kNumElements = 5;
constexpr span<const int> span(kArray);
static constexpr int kOverlappingStartIndexes[] = {-4, 0, 3, 4};
static constexpr int kNonOverlappingStartIndexes[] = {-7, -5, 5, 7};
// Overlapping ranges.
for (const int dest_start_index : kOverlappingStartIndexes) {
EXPECT_FALSE(CheckedContiguousIterator<const int>::IsRangeMoveSafe(
span.begin(), span.end(),
CheckedContiguousIterator<const int>(
span.data() + dest_start_index,
span.data() + dest_start_index + kNumElements)));
EXPECT_FALSE(CheckedContiguousConstIterator<const int>::IsRangeMoveSafe(
std::cbegin(span), std::cend(span),
CheckedContiguousConstIterator<const int>(
span.data() + dest_start_index,
span.data() + dest_start_index + kNumElements)));
}
// Non-overlapping ranges.
for (const int dest_start_index : kNonOverlappingStartIndexes) {
EXPECT_TRUE(CheckedContiguousIterator<const int>::IsRangeMoveSafe(
span.begin(), span.end(),
CheckedContiguousIterator<const int>(
span.data() + dest_start_index,
span.data() + dest_start_index + kNumElements)));
EXPECT_TRUE(CheckedContiguousConstIterator<const int>::IsRangeMoveSafe(
std::cbegin(span), std::cend(span),
CheckedContiguousConstIterator<const int>(
span.data() + dest_start_index,
span.data() + dest_start_index + kNumElements)));
}
// IsRangeMoveSafe is true if the length to be moved is 0.
EXPECT_TRUE(CheckedContiguousIterator<const int>::IsRangeMoveSafe(
span.begin(), span.begin(),
CheckedContiguousIterator<const int>(span.data(), span.data())));
EXPECT_TRUE(CheckedContiguousConstIterator<const int>::IsRangeMoveSafe(
std::cbegin(span), std::cbegin(span),
CheckedContiguousConstIterator<const int>(span.data(), span.data())));
// IsRangeMoveSafe is false if end < begin.
EXPECT_FALSE(CheckedContiguousIterator<const int>::IsRangeMoveSafe(
span.end(), span.begin(),
CheckedContiguousIterator<const int>(span.data(), span.data())));
EXPECT_FALSE(CheckedContiguousConstIterator<const int>::IsRangeMoveSafe(
std::cend(span), std::cbegin(span),
CheckedContiguousConstIterator<const int>(span.data(), span.data())));
}
// Pigweed: gMock matchers are not yet supported.
TEST(SpanTest, Sort) {
int array[] = {5, 4, 3, 2, 1};
span<int> dynamic_span = array;
std::sort(dynamic_span.begin(), dynamic_span.end());
EXPECT_THAT(array, ElementsAre(1, 2, 3, 4, 5));
std::sort(dynamic_span.rbegin(), dynamic_span.rend());
EXPECT_THAT(array, ElementsAre(5, 4, 3, 2, 1));
span<int, 5> static_span = array;
std::sort(static_span.rbegin(), static_span.rend(), std::greater<>());
EXPECT_THAT(array, ElementsAre(1, 2, 3, 4, 5));
std::sort(static_span.begin(), static_span.end(), std::greater<>());
EXPECT_THAT(array, ElementsAre(5, 4, 3, 2, 1));
}
#endif // 0
TEST(SpanTest, SpanExtentConversions) {
// Statically checks that various conversions between spans of dynamic and
// static extent are possible or not.
// This test fails with the real C++20 std::span, so skip it.
// static_assert(
// !std::is_constructible<span<int, 0>, span<int>>::value,
// "Error: static span should not be constructible from dynamic span");
static_assert(!std::is_constructible<span<int, 2>, span<int, 1>>::value,
"Error: static span should not be constructible from static "
"span with different extent");
static_assert(std::is_convertible<span<int, 0>, span<int>>::value,
"Error: static span should be convertible to dynamic span");
static_assert(std::is_convertible<span<int>, span<int>>::value,
"Error: dynamic span should be convertible to dynamic span");
static_assert(std::is_convertible<span<int, 2>, span<int, 2>>::value,
"Error: static span should be convertible to static span");
}
TEST(SpanTest, IteratorConversions) {
static_assert(std::is_convertible<span<int>::iterator,
span<const int>::iterator>::value,
"Error: iterator should be convertible to const iterator");
static_assert(!std::is_convertible<span<const int>::iterator,
span<int>::iterator>::value,
"Error: const iterator should not be convertible to iterator");
}
// NOLINTEND(modernize-unary-static-assert)
} // namespace pw