std::basic_string<CharT,Traits,Allocator>::copy
From cppreference.com
< cpp | string | basic string
size_type copy( CharT* dest, size_type count, size_type pos = 0 ) const; |
(until C++20) | |
constexpr size_type copy( CharT* dest, size_type count, size_type pos = 0 ) const; |
(since C++20) | |
Copies a substring [
pos,
pos + count)
to character string pointed to by dest. If the requested substring lasts past the end of the string, or if count == npos, the copied substring is [
pos,
size()
)
. The resulting character string is not null-terminated.
Contents |
[edit] Parameters
dest | - | pointer to the destination character string |
count | - | length of the substring |
pos | - | position of the first character to include |
[edit] Return value
Number of characters copied.
[edit] Exceptions
std::out_of_range if pos > size().
[edit] Complexity
Linear in count.
[edit] Example
Run this code
#include <iostream> #include <string> int main() { std::string foo("WINE"); // brace-initialization initializes all characters to 0, // providing a null-terminator char bar[4]{}; // do not copy the last char, to guarantee null-termination foo.copy(bar, sizeof bar - 1); std::cout << bar << '\n'; // requires bar to be null-terminated }
Output:
WIN
[edit] See also
returns a substring (public member function) | |
(C++17) |
copies characters (public member function of std::basic_string_view<CharT,Traits> )
|
(C++11) |
copies a range of elements to a new location (function template) |
copies one buffer to another (function) |