blob: 4c4ab5628c95a5146ba0e3976461f23ab7bd15c5 [file] [log] [blame]
// 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
// 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.
#pragma once
#include <type_traits>
namespace pw::kvs {
namespace internal {
template <typename T, typename = decltype(std::span(std::declval<T>()))>
constexpr bool ConvertsToSpan(int) {
return true;
// If the expression std::span(T) fails, then the type can't be converted to a
// std::span.
template <typename T>
constexpr bool ConvertsToSpan(...) {
return false;
} // namespace internal
// Traits class to detect if the type converts to a std::span.
template <typename T>
struct ConvertsToSpan
: public std::bool_constant<
internal::ConvertsToSpan<std::remove_reference_t<T>>(0)> {};
} // namespace pw::kvs