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// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
/*
* Ceph - scalable distributed file system
*
* Copyright (C) 2011 New Dream Network
*
* This is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1, as published by the Free Software
* Foundation. See file COPYING.
*
*/
#ifndef CEPH_COMMON_STRTOL_H
#define CEPH_COMMON_STRTOL_H
#include <charconv>
#include <cinttypes>
#include <cstdlib>
#include <optional>
#include <string>
#include <string_view>
#include <system_error>
#include <type_traits>
namespace ceph {
// Wrappers around std::from_chars.
//
// Why do we want this instead of strtol and friends? Because the
// string doesn't have to be NUL-terminated! (Also, for a lot of
// purposes, just putting a string_view in and getting an optional out
// is friendly.)
//
// Returns the found number on success. Returns an empty optional on
// failure OR on trailing characters.
// Sadly GCC < 11 is missing the floating point versions.
template<typename T>
auto parse(std::string_view s, int base = 10)
-> std::enable_if_t<std::is_integral_v<T>, std::optional<T>>
{
T t;
auto r = std::from_chars(s.data(), s.data() + s.size(), t, base);
if ((r.ec != std::errc{}) || (r.ptr != s.data() + s.size())) {
return std::nullopt;
}
return t;
}
// As above, but succeed on trailing characters and trim the supplied
// string_view to remove the parsed number. Set the supplied
// string_view to empty if it ends with the number.
template<typename T>
auto consume(std::string_view& s, int base = 10)
-> std::enable_if_t<std::is_integral_v<T>, std::optional<T>>
{
T t;
auto r = std::from_chars(s.data(), s.data() + s.size(), t, base);
if (r.ec != std::errc{})
return std::nullopt;
if (r.ptr == s.data() + s.size()) {
s = std::string_view{};
} else {
s.remove_prefix(r.ptr - s.data());
}
return t;
}
} // namespace ceph
bool strict_strtob(const char* str, std::string *err);
long long strict_strtoll(std::string_view str, int base, std::string *err);
int strict_strtol(std::string_view str, int base, std::string *err);
double strict_strtod(std::string_view str, std::string *err);
float strict_strtof(std::string_view str, std::string *err);
uint64_t strict_iecstrtoll(std::string_view str, std::string *err);
template<typename T>
T strict_iec_cast(std::string_view str, std::string *err);
template<typename T>
T strict_si_cast(std::string_view str, std::string *err);
/* On enter buf points to the end of the buffer, e.g. where the least
* significant digit of the input number will be printed. Returns pointer to
* where the most significant digit were printed, including zero padding.
* Does NOT add zero at the end of buffer, this is responsibility of the caller.
*/
template<typename T, const unsigned base = 10, const unsigned width = 1>
static inline
char* ritoa(T u, char *buf)
{
static_assert(std::is_unsigned_v<T>, "signed types are not supported");
static_assert(base <= 16, "extend character map below to support higher bases");
unsigned digits = 0;
while (u) {
*--buf = "0123456789abcdef"[u % base];
u /= base;
digits++;
}
while (digits++ < width)
*--buf = '0';
return buf;
}
#endif
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