size_type find_first_not_of( const basic_string& str, size_type pos = 0 ) const; | (1) | |
size_type find_first_not_of( const CharT* s, size_type pos, size_type count ) const; | (2) | |
size_type find_first_not_of( const CharT* s, size_type pos = 0 ) const; | (3) | |
size_type find_first_not_of( CharT ch, size_type pos = 0 ) const; | (4) |
Finds the first character equal to none of the characters in the given character sequence. The search considers only the interval [pos, size()). If the character is not present in the interval, npos will be returned.
1) Finds the first character equal to none of characters in
str. 2) Finds the first character equal to none of characters in the first
count characters of the character string pointed to by s. s can include null characters. 3) Finds the first character equal to none of characters in character string pointed to by
s. The length of the string is determined by the first null character. 4) Finds the first character not equal to
ch.Parameters
| str | - | string identifying characters to search for |
| pos | - | position for the seach to start from |
| count | - | length of character string identifying characters to search for |
| s | - | pointer to a character string identifying characters to search for |
| ch | - | character identifying characters to search for |
Return value
Position of the found character or npos if no such character is found.
Exceptions
| 1-4) (none) | (until C++11) |
| 1,4) noexcept specification: noexcept 2,3) (none) | (since C++11) (until C++14) |
| 1) noexcept specification: noexcept 2,3,4) (none) | (since C++14) |
Notes
These functions use traits::eq() to test the characters for equality.
Example
#include <string>
#include <iostream>
int main() {
std::string to_search = "Some data with %MACROS to substitute";
std::cout << "Before: " << to_search << '\n';
auto pos = std::string::npos;
while ((pos = to_search.find('%')) != std::string::npos) {
// Permit uppercase letters, lowercase letters and numbers in macro names
const auto after = to_search.find_first_not_of("ABCDEFGHIJKLMOPQRSTUVWXYZabcdefghijklmopqrstuvwxyz0123456789", pos + 1);
// Now to_search[pos] == '%' and to_search[after] == ' ' (after the 'S')
if(after != std::string::npos)
to_search.replace(pos, after - pos, "some very nice macros");
}
std::cout << "After: " << to_search << '\n';
}Output:
Before: Some data with %MACROS to substitute After: Some data with some very nice macros to substitute
See also
| find characters in the string (public member function) | |
| find the last occurrence of a substring (public member function) | |
| find first occurrence of characters (public member function) | |
| find last occurrence of characters (public member function) | |
| find last absence of characters (public member function) |
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