NAME¶

std::wstring_convert::converted - std::wstring_convert::converted

Synopsis¶

Defined in header <locale>
std::size_t converted() const noexcept;

Returns the number of source characters that were processed by the most recent
from_bytes() or to_bytes().

Return value¶

The number of characters consumed by the most recent conversion operation.

Example¶

// Run this code

#include <iostream>
#include <string>
#include <locale>
#include <codecvt>
int main()
{
std::string utf8 = u8"z\u00df\u6c34\U0001d10b"; // or u8"zß水𝄋"
// or "\x7a\xc3\x9f\xe6\xb0\xb4\xf0\x9d\x84\x8b";
std::cout << "original UTF-8 string size: " << utf8.size() << '\n';

// the UTF-8 - UTF-32 standard conversion facet
std::wstring_convert<std::codecvt_utf8<char32_t>, char32_t> cvt;

// UTF-8 to UTF-32
std::u32string utf32 = cvt.from_bytes(utf8);
std::cout << "UTF-32 string size: " << utf32.size() << '\n';
std::cout << "converted() == " << cvt.converted() << '\n';
// UTF-32 to UTF-8
utf8 = cvt.to_bytes(utf32);
std::cout << "new UTF-8 string size: " << utf8.size() << '\n';
std::cout << "converted() == " << cvt.converted() << '\n';
}

Output:¶

original UTF-8 string size: 10
UTF-32 string size: 4
converted() == 10
new UTF-8 string size: 10
converted() == 4

Defect reports

The following behavior-changing defect reports were applied retroactively to
previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 2174 C++11 wstring_convert::converted was not required to required
be noexcept

See also¶

to_bytes converts a wide string into a byte string
(public member function)
from_bytes converts a byte string into a wide string
(public member function)