| 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 wcsrtombs(char* dst, constwchar_t** src, | ||
Converts a sequence of wide characters from the array whose first element is pointed to by*src to its narrow multibyte representation that begins in the conversion state described by*ps. Ifdst is not null, converted characters are stored in the successive elements of the char array pointed to bydst. No more thanlen bytes are written to the destination array.
Each character is converted as if by a call tostd::wcrtomb. The conversion stops if:
Contents |
| dst | - | pointer to narrow character array where the multibyte characters will be stored |
| src | - | pointer to pointer to the first element of a null-terminated wide string |
| len | - | number of bytes available in the array pointed to by dst |
| ps | - | pointer to the conversion state object |
On success, returns the number of bytes (including any shift sequences, but excluding the terminating'\0') written to the character array whose first element is pointed to bydst. Ifdst is a null pointer, returns the number of bytes that would have been written (again, excluding the terminating null character'\0').
On conversion error (if invalid wide character was encountered), returnsstatic_cast<std::size_t>(-1), storesEILSEQ inerrno, and leaves*ps in unspecified state.
#include <clocale>#include <cwchar>#include <iostream>#include <string>#include <vector> void print_wide(constwchar_t* wstr){std::mbstate_t state=std::mbstate_t();std::size_t len=1+ std::wcsrtombs(nullptr,&wstr,0,&state);std::vector<char> mbstr(len); std::wcsrtombs(&mbstr[0],&wstr, mbstr.size(),&state);std::cout<<"multibyte string: "<<&mbstr[0]<<'\n'<<"Length, including '\\0': "<< mbstr.size()<<'\n';} int main(){std::setlocale(LC_ALL,"en_US.utf8");// UTF-8 narrow multibyte encodingconstwchar_t* wstr= L"z\u00df\u6c34\U0001d10b";// or L"zß水𝄋" print_wide(wstr);}
Output:
multibyte string: zß水𝄋Length, including '\0': 11
| converts a wide character to its multibyte representation, given state (function)[edit] | |
| converts a narrow multibyte character string to wide string, given state (function)[edit] | |
[virtual] | converts a string fromInternT toExternT, such as when writing to file(virtual protected member function of std::codecvt<InternT,ExternT,StateT>)[edit] |
C documentation forwcsrtombs | |