std::wcstok - cppreference.com (original) (raw)

| | | | | ------------------------------------------------------------------------------ | | | | wchar_t* wcstok( wchar_t* str, const wchar_t* delim, wchar_t ** ptr); | | |

Finds the next token in a null-terminated wide string pointed to by str. The separator characters are identified by null-terminated wide string pointed to by delim.

This function is designed to be called multiples times to obtain successive tokens from the same string.

• If str != nullptr, the call is treated as the first call to std::wcstok for this particular wide string. The function searches for the first wide character which is not contained in delim.

• If no such wide character was found, there are no tokens in str at all, and the function returns a null pointer.

• If such wide character was found, it is the beginning of the token. The function then searches from that point on for the first wide character that is contained in delim.

• If no such wide character was found, str has only one token, and future calls to std::wcstok will return a null pointer.

• If such wide character was found, it is replaced by the null wide character L'\0' and the parser state (typically a pointer to the following wide character) is stored in the user-provided location *ptr.

• The function then returns the pointer to the beginning of the token.

• If str == nullptr, the call is treated as a subsequent calls to std::wcstok: the function continues from where it left in previous invocation with the same *ptr. The behavior is the same as if the pointer to the wide character that follows the last detected token is passed as str.

[edit] Parameters

[edit] Return value

Pointer to the beginning of the next token or null pointer if there are no more tokens.

[edit] Note

This function is destructive: it writes the L'\0' characters in the elements of the string str. In particular, a wide string literal cannot be used as the first argument of std::wcstok.

Unlike std::strtok, this function does not update static storage: it stores the parser state in the user-provided location.

Unlike most other tokenizers, the delimiters in std::wcstok can be different for each subsequent token, and can even depend on the contents of the previous tokens.

[edit] Example

#include #include   int main() { wchar_t input[100] = L"A bird came down the walk"; wchar_t* buffer; wchar_t* token = std::wcstok(input, L" ", &buffer); while (token) { std::wcout << token << '\n'; token = std::wcstok(nullptr, L" ", &buffer); } }

Output:

A bird came down the walk

[edit] See also