| Localization library | |||||||||||||||||||||||||
| Regular expressions library(C++11) | |||||||||||||||||||||||||
| Formatting library(C++20) | |||||||||||||||||||||||||
| Null-terminated sequence utilities | |||||||||||||||||||||||||
| Byte strings | |||||||||||||||||||||||||
| Multibyte strings | |||||||||||||||||||||||||
| Wide strings | |||||||||||||||||||||||||
| Primitive numeric conversions | |||||||||||||||||||||||||
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| Text encoding identifications | |||||||||||||||||||||||||
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Defined in header <cstdlib> | ||
std::size_t mbstowcs(wchar_t* dst,constchar* src,std::size_t len); | ||
Converts a multibyte character string from the array whose first element is pointed to bysrc to its wide character representation. Converted characters are stored in the successive elements of the array pointed to bydst. No more thanlen wide characters are written to the destination array.
Each character is converted as if by a call tostd::mbtowc, except that the mbtowc conversion state is unaffected. The conversion stops if:
Contents |
In most implementations, this function updates a global static object of typestd::mbstate_t as it processes through the string, and cannot be called simultaneously by two threads,std::mbsrtowcs should be used in such cases.
POSIX specifies a common extension: ifdst is a null pointer, this function returns the number of wide characters that would be written todst, if converted. Similar behavior is standard forstd::mbsrtowcs.
| dst | - | pointer to wide character array where the wide string will be stored |
| src | - | pointer to the first element of a null-terminated multibyte string to convert |
| len | - | number of wide characters available in the array pointed to by dst |
On success, returns the number of wide characters, excluding the terminatingL'\0', written to the destination array.
On conversion error (if invalid multibyte character was encountered), returnsstatic_cast<std::size_t>(-1).
#include <clocale>#include <cstdlib>#include <iostream> int main(){std::setlocale(LC_ALL,"en_US.utf8");std::wcout.imbue(std::locale("en_US.utf8"));constchar* mbstr="z\u00df\u6c34\U0001f34c";// or u8"zß水🍌"// or "\x7a\xc3\x9f\xe6\xb0\xb4\xf0\x9f\x8d\x8c";wchar_t wstr[5]; std::mbstowcs(wstr, mbstr,5);std::wcout<<"wide string: "<< wstr<<'\n';}
Output:
wide string: zß水🍌
| converts a narrow multibyte character string to wide string, given state (function)[edit] | |
| converts a wide string to narrow multibyte character string (function)[edit] | |
[virtual] | converts a string fromExternT toInternT, such as when reading from file(virtual protected member function of std::codecvt<InternT,ExternT,StateT>)[edit] |
C documentation formbstowcs | |
