| // Copyright 2019 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. |
| #pragma once |
| |
| #include <cstddef> |
| |
| namespace pw::string { |
| |
| // Calculates the length of a null-terminated string up to the specified maximum |
| // length. If str is nullptr, returns 0. |
| // |
| // This function is a constexpr version of C11's strnlen_s. |
| constexpr size_t Length(const char* str, size_t max_len) { |
| size_t length = 0; |
| |
| if (str != nullptr) { |
| for (; length < max_len; ++length) { |
| if (str[length] == '\0') { |
| break; |
| } |
| } |
| } |
| |
| return length; |
| } |
| |
| } // namespace pw::string |
