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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14
// <charconv>
// constexpr from_chars_result from_chars(const char* first, const char* last,
// Integral& value, int base = 10)
#include <charconv>
#include "test_macros.h"
#include "charconv_test_helpers.h"
template <typename T>
struct test_basics
{
TEST_CONSTEXPR_CXX23 void operator()()
{
std::from_chars_result r;
T x;
{
char s[] = "001x";
// the expected form of the subject sequence is a sequence of
// letters and digits representing an integer with the radix
// specified by base (C11 7.22.1.4/3)
r = std::from_chars(s, s + sizeof(s), x);
assert(r.ec == std::errc{});
assert(r.ptr == s + 3);
assert(x == 1);
}
{
// The string has more characters than valid in an 128-bit value.
char s[] = "0X7BAtSGHDkEIXZgQRfYChLpOzRnM ";
// The letters from a (or A) through z (or Z) are ascribed the
// values 10 through 35; (C11 7.22.1.4/3)
r = std::from_chars(s, s + sizeof(s), x, 36);
assert(r.ec == std::errc::result_out_of_range);
// The member ptr of the return value points to the first character
// not matching the pattern
assert(r.ptr == s + sizeof(s) - 2);
assert(x == 1);
// no "0x" or "0X" prefix shall appear if the value of base is 16
r = std::from_chars(s, s + sizeof(s), x, 16);
assert(r.ec == std::errc{});
assert(r.ptr == s + 1);
assert(x == 0);
// only letters and digits whose ascribed values are less than that
// of base are permitted. (C11 7.22.1.4/3)
r = std::from_chars(s + 2, s + sizeof(s), x, 12);
// If the parsed value is not in the range representable by the type
// of value,
if (!fits_in<T>(1150))
{
// value is unmodified and
assert(x == 0);
// the member ec of the return value is equal to
// errc::result_out_of_range
assert(r.ec == std::errc::result_out_of_range);
}
else
{
// Otherwise, value is set to the parsed value,
assert(x == 1150);
// and the member ec is value-initialized.
assert(r.ec == std::errc{});
}
assert(r.ptr == s + 5);
}
}
};
template <typename T>
struct test_signed
{
TEST_CONSTEXPR_CXX23 void operator()()
{
std::from_chars_result r;
T x = 42;
{
// If the pattern allows for an optional sign,
// but the string has no digit characters following the sign,
char s[] = "- 9+12";
r = std::from_chars(s, s + sizeof(s), x);
// value is unmodified,
assert(x == 42);
// no characters match the pattern.
assert(r.ptr == s);
assert(r.ec == std::errc::invalid_argument);
}
{
char s[] = "9+12";
r = std::from_chars(s, s + sizeof(s), x);
assert(r.ec == std::errc{});
// The member ptr of the return value points to the first character
// not matching the pattern,
assert(r.ptr == s + 1);
assert(x == 9);
}
{
char s[] = "12";
r = std::from_chars(s, s + 2, x);
assert(r.ec == std::errc{});
// or has the value last if all characters match.
assert(r.ptr == s + 2);
assert(x == 12);
}
{
// '-' is the only sign that may appear
char s[] = "+30";
// If no characters match the pattern,
r = std::from_chars(s, s + sizeof(s), x);
// value is unmodified,
assert(x == 12);
// the member ptr of the return value is first and
assert(r.ptr == s);
// the member ec is equal to errc::invalid_argument.
assert(r.ec == std::errc::invalid_argument);
}
}
};
TEST_CONSTEXPR_CXX23 bool test()
{
run<test_basics>(integrals);
run<test_signed>(all_signed);
return true;
}
int main(int, char**) {
test();
#if TEST_STD_VER > 20
static_assert(test());
#endif
return 0;
}
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