std::mbrtowc
| Defined in header  <cwchar> | ||
| std::size_t mbrtowc( wchar_t* pwc,                      const char* s, | ||
Converts a narrow multibyte character to a wide character.
If s is not a null pointer, inspects at most n bytes of the multibyte character string, beginning with the byte pointed to by s to determine the number of bytes necessary to complete the next multibyte character (including any shift sequences). If the function determines that the next multibyte character in s is complete and valid, converts it to the corresponding wide character and stores it in *pwc (if pwc is not null).
If s is a null pointer, the values of n and pwc are ignored and call is equivalent to std::mbrtowc(NULL, "", 1, ps).
If the wide character produced is the null character, the conversion state stored in *ps is the initial shift state.
| Contents | 
[edit] Parameters
| pwc | - | pointer to the location where the resulting wide character will be written | 
| s | - | pointer to the multibyte character string used as input | 
| n | - | limit on the number of bytes in s that can be examined | 
| ps | - | pointer to the conversion state used when interpreting the multibyte string | 
[edit] Return value
The first of the following that applies:
-  0 if the character converted from s(and stored in pwc if non-null) was the null character
-  the number of bytes [1...n] of the multibyte character successfully converted from s
-  static_cast<std::size_t>(-2) if the next nbytes constitute an incomplete, but so far valid, multibyte character. Nothing is written to *pwc.
-  static_cast<std::size_t>(-1) if encoding error occurs. Nothing is written to *pwc, the value EILSEQ is stored in errno and the value of *ps is left unspecified.
[edit] Example
#include <iostream> #include <clocale> #include <cstring> #include <cwchar> void print_mb(const char* ptr) { std::mbstate_t state = std::mbstate_t(); // initial state const char* end = ptr + std::strlen(ptr); int len; wchar_t wc; while((len = std::mbrtowc(&wc, ptr, end-ptr, &state)) > 0) { std::wcout << "Next " << len << " bytes are the character " << wc << '\n'; ptr += len; } } int main() { std::setlocale(LC_ALL, "en_US.utf8"); // UTF-8 narrow multibyte encoding const char* str = u8"z\u00df\u6c34\U0001d10b"; // or u8"zß水𝄋" // or "\x7a\xc3\x9f\xe6\xb0\xb4\xf0\x9d\x84\x8b"; print_mb(str); }
Output:
Next 1 bytes are the character z Next 2 bytes are the character ß Next 3 bytes are the character 水 Next 4 bytes are the character 𝄋
[edit] See also
| converts the next multibyte character to wide character (function) | |
| converts a wide character to its multibyte representation, given state (function) | |
| [virtual] | converts a string from externT to internT, such as when reading from file (virtual protected member function of std::codecvt) | 
| C documentation for mbrtowc | |


