Defined in header <cwchar> | ||
|---|---|---|
int mbsinit( const std::mbstate_t* ps); |
If ps is not a null pointer, the mbsinit function determines whether the pointed-to std::mbstate_t object describes the initial conversion state.
Although a zero-initialized std::mbstate_t always represents the initial conversion state, there may be other values of std::mbstate_t that also represent the initial conversion state.
| ps | - | pointer to the std::mbstate_t object to examine |
0 if ps is not a null pointer and does not represent the initial conversion state, nonzero value otherwise.
#include <clocale>
#include <string>
#include <iostream>
#include <cwchar>
int main()
{
// allow mbrlen() to work with UTF-8 multibyte encoding
std::setlocale(LC_ALL, "en_US.utf8");
// UTF-8 narrow multibyte encoding
std::string str = u8"水"; // or u8"\u6c34" or "\xe6\xb0\xb4"
std::mbstate_t mb = std::mbstate_t();
(void)std::mbrlen(&str[0], 1, &mb);
if (!std::mbsinit(&mb)) {
std::cout << "After processing the first 1 byte of " << str
<< " the conversion state is not initial\n";
}
(void)std::mbrlen(&str[1], str.size()-1, &mb);
if (std::mbsinit(&mb)) {
std::cout << "After processing the remaining 2 bytes of " << str
<< ", the conversion state is initial conversion state\n";
}
}Output:
After processing the first 1 byte of 水 the conversion state is not initial After processing the remaining 2 bytes of 水, the conversion state is initial conversion state
| conversion state information necessary to iterate multibyte character strings (class) |
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