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/*
* Copyright 2017 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "rtc_base/string_to_number.h"
#include <ctype.h>
#include <cerrno>
#include <cstdlib>
#include "rtc_base/checks.h"
namespace webrtc {
namespace string_to_number_internal {
std::optional<signed_type> ParseSigned(absl::string_view str, int base) {
if (str.empty())
return std::nullopt;
if (isdigit(static_cast<unsigned char>(str[0])) || str[0] == '-') {
std::string str_str(str);
char* end = nullptr;
errno = 0;
const signed_type value = std::strtoll(str_str.c_str(), &end, base);
// Check for errors and also make sure that there were no embedded nuls in
// the input string.
if (end == str_str.c_str() + str_str.size() && errno == 0) {
return value;
}
}
return std::nullopt;
}
std::optional<unsigned_type> ParseUnsigned(absl::string_view str, int base) {
if (str.empty())
return std::nullopt;
if (isdigit(static_cast<unsigned char>(str[0])) || str[0] == '-') {
std::string str_str(str);
// Explicitly discard negative values. std::strtoull parsing causes unsigned
// wraparound. We cannot just reject values that start with -, though, since
// -0 is perfectly fine, as is -0000000000000000000000000000000.
const bool is_negative = str[0] == '-';
char* end = nullptr;
errno = 0;
const unsigned_type value = std::strtoull(str_str.c_str(), &end, base);
// Check for errors and also make sure that there were no embedded nuls in
// the input string.
if (end == str_str.c_str() + str_str.size() && errno == 0 &&
(value == 0 || !is_negative)) {
return value;
}
}
return std::nullopt;
}
template <typename T>
T StrToT(const char* str, char** str_end);
template <>
inline float StrToT(const char* str, char** str_end) {
return std::strtof(str, str_end);
}
template <>
inline double StrToT(const char* str, char** str_end) {
return std::strtod(str, str_end);
}
template <>
inline long double StrToT(const char* str, char** str_end) {
return std::strtold(str, str_end);
}
template <typename T>
std::optional<T> ParseFloatingPoint(absl::string_view str) {
if (str.empty())
return std::nullopt;
if (str[0] == '\0')
return std::nullopt;
std::string str_str(str);
char* end = nullptr;
errno = 0;
const T value = StrToT<T>(str_str.c_str(), &end);
if (end == str_str.c_str() + str_str.size() && errno == 0) {
return value;
}
return std::nullopt;
}
template std::optional<float> ParseFloatingPoint(absl::string_view str);
template std::optional<double> ParseFloatingPoint(absl::string_view str);
template std::optional<long double> ParseFloatingPoint(absl::string_view str);
} // namespace string_to_number_internal
} // namespace webrtc
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