std::erase, std::erase_if (std::)

{{cpp/container/{{{1}}}/navbar}}

Defined in header [[cpp/header/{{{1}}}|<{{{1}}}>]]
template< ..., class U > void erase(std::{{{1}}}<...>& c, const U& value);	(1)	(since C++20)
template< ..., class Pred > void erase_if(std::{{{1}}}<...>& c, Pred pred);	(2)	(since C++20)

1) Erases all elements that compare equal to value from the container.

2) Erases all elements that satisfy the predicate pred from the container.

Parameters

c	-	container from which to erase
value	-	value to be removed
pred	-	unary predicate which returns ​true if the element should be erased. The expression pred(v) must be convertible to bool for every argument v of type (possibly const) T, regardless of value category, and must not modify v. Thus, a parameter type of T&is not allowed, nor is T unless for T a move is equivalent to a copy(since C++11). ​

Complexity

Linear.

Example

Run this code

#include <iostream>
#include <numeric>
#include <{{{1}}}>
 
void print_container(const std::{{{1}}}<char>& v)
{
    for (auto x : v) {
        std::cout << x << ' ';
    }
    std::cout << '\n';
}
 
int main()
{
    std::{{{1}}}<char> cnt(10);
    std::iota(cnt.begin(), cnt.end(), '0');
 
    std::cout << "Init:\n";
    print_container(v);
 
    std::erase(v, '5');
    std::cout << "Erase \'5\':\n";
    print_container(v);
 
    std::erase_if(v, [](char x) { return (x - '0') % 2 == 0; });
    std::cout << "Erase all even numbers:\n";
    print_container(v);
}

Output:

Init:
0 1 2 3 4 5 6 7 8 9 
Erase 5:
0 1 2 3 4 6 7 8 9 
Erase all even numbers:
1 3 7 9

See also

removeremove_if

removes elements satisfying specific criteria (function template)