| 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 <cwchar> | ||
std::size_t mbsrtowcs(wchar_t* dst, constchar** src, | ||
Converts a null-terminated multibyte character sequence, which begins in the conversion state described by*ps, from the array whose first element is pointed to by*src to its wide character representation. Ifdst is not null, converted characters are stored in the successive elements of the wchar_t array pointed to bydst. No more thanlen wide characters are written to the destination array.
Each multibyte character is converted as if by a call tostd::mbrtowc. The conversion stops if:
*ps represents the initial shift state.Contents |
| dst | - | pointer to wide character array where the results will be stored |
| src | - | pointer to pointer to the first element of a null-terminated multibyte string |
| len | - | number of wide characters available in the array pointed to by dst |
| ps | - | pointer to the conversion state object |
On success, returns the number of wide characters, excluding the terminatingL'\0', written to the character array. Ifdst is a null pointer, returns the number of wide characters that would have been written given unlimited length.
On conversion error (if invalid multibyte character was encountered), returnsstatic_cast<std::size_t>(-1), storesEILSEQ inerrno, and leaves*ps in unspecified state.
This function moves thesrc pointer to the end of the converted multibyte string. This doesn't happen ifdst is a null pointer.
#include <clocale>#include <cwchar>#include <iostream>#include <vector> void print_as_wide(constchar* mbstr){std::mbstate_t state=std::mbstate_t();std::size_t len=1+ std::mbsrtowcs(nullptr,&mbstr,0,&state);std::vector<wchar_t> wstr(len); std::mbsrtowcs(&wstr[0],&mbstr, wstr.size(),&state);std::wcout<<"Wide string: "<<&wstr[0]<<'\n'<<"The length, including '\\0': "<< wstr.size()<<'\n';} int main(){std::setlocale(LC_ALL,"en_US.utf8");constchar* mbstr="z\u00df\u6c34\U0001f34c";// or u8"zß水🍌" print_as_wide(mbstr);}
Output:
Wide string: zß水🍌The length, including '\0': 5
| converts the next multibyte character to wide character, given state (function)[edit] | |
| converts a wide string to narrow multibyte character string, given state (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 formbsrtowcs | |
