std::btowc
Defined in header <cwchar> | | |
|---|---|---|
std::wint_t btowc( int c ); | | |
扩展单字节字符。c与它的宽特性相当。
大多数多字节字符编码使用单字节代码来表示ASCII字符集中的字符。此函数可用于将这些字符转换为wchar_t...
参数
c | - | single-byte character to widen |
|---|
返回值
WEOF如果c是EOF...
宽字符表示c如果(unsigned char)c是处于初始移位状态的有效单字节字符，WEOF否则。
例
二次
#include <iostream>
#include <cwchar>
#include <clocale>
void try_widen(char c)
{
std::wint_t w = std::btowc(c);
if(w != WEOF)
std::cout << "The single-byte character " << +(unsigned char)c
<< " widens to " << +w << '\n';
else
std::cout << "The single-byte character " << +(unsigned char)c
<< " failed to widen\n";
}
int main()
{
std::setlocale(LC_ALL, "lt_LT.iso88594");
std::cout << std::hex << std::showbase << "In Lithuanian ISO-8859-4 locale:\n";
try_widen('A');
try_widen('\xdf'); // German letter ß (U+00df) in ISO-8859-4
try_widen('\xf9'); // Lithuanian letter ų (U+0173) in ISO-8859-4
std::setlocale(LC_ALL, "lt_LT.utf8");
std::cout << "In Lithuanian UTF-8 locale:\n";
try_widen('A');
try_widen('\xdf');
try_widen('\xf9');
}二次
产出：
二次
In Lithuanian ISO-8859-4 locale:
The single-byte character 0x41 widens to 0x41
The single-byte character 0xdf widens to 0xdf
The single-byte character 0xf9 widens to 0x173
In Lithuanian UTF-8 locale:
The single-byte character 0x41 widens to 0x41
The single-byte character 0xdf failed to widen
The single-byte character 0xf9 failed to widen二次
另见
wctob | narrows a wide character to a single-byte narrow character, if possible (function) |
|---|---|
do_widen virtual | converts a character or characters from char to charT (virtual protected member function of std::ctype) |
c btwc文件
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