std::erase, std::erase_if(std::inplace_vector)
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Tables
std::inplace_vector
erase(std::inplace_vector)erase_if(std::inplace_vector)
Defined in header
<inplace_vector>
template< class T, std::size_t N, class U = T >
(1)
(since C++26)
constexpr typename std::inplace_vector <T, N>::size_type
template< class T, std::size_t N, class Pred >
(2)
(since C++26)
constexpr typename std::inplace_vector <T, N>::size_type
1) Erases all elements that compare equal to value from the container c. Equivalent to
auto it = std::remove(c.begin(), c.end(), value);
auto r = std::distance (it, c.end());
c.erase(it, c.end());
return r;.
auto r = std::distance (it, c.end());
c.erase(it, c.end());
return r;.
2) Erases all elements that satisfy the predicate pred from the container c. Equivalent to
auto it = std::remove_if (c.begin(), c.end(), pred);
auto r = std::distance (it, c.end());
c.erase(it, c.end());
return r;.
auto r = std::distance (it, c.end());
c.erase(it, c.end());
return r;.
[edit] 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).
[edit] Return value
The number of erased elements.
[edit] Complexity
Linear.
[edit] Example
Run this code
#include <cassert> #include <complex> #include <inplace_vector> #include <numeric> #include <print> int main() { std::inplace_vector <int, 10> v(10, 0); std::ranges::iota (v, 0); std::println ("Initially, v = {}", v); auto erased = std::erase (v, 3); std::println ("After erase(v, 3), v = {}", v); assert (erased == 1); erased = std::erase_if (v, [](int x) { return x % 2 == 0; }); std::println ("After erasing all even numbers, v = {}", v); std::println ("Erased even numbers: {}", erased); std::inplace_vector <std::complex <double>> nums{{2, 2}, {4, 2}, {4, 8}, {4, 2}}; std::erase (nums, {4, 2}); // since U = T, the value type can be ommited std::println ("After erase {4, 2}, nums = {}", nums); }
Output:
Initially, v = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
After erase(v, 3), v = [0, 1, 2, 4, 5, 6, 7, 8, 9]
After erasing all even numbers, v = [1, 5, 7, 9]
Erased even numbers: 5
After erase {4, 2}, nums = [(2,2), (4,8)]