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

 

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std::inplace_vector

Member types
Member functions
inplace_vector::inplace_vector inplace_vector::~inplace_vector    inplace_vector::operator= inplace_vector::assign inplace_vector::assign_range Size and capacity inplace_vector::empty inplace_vector::size inplace_vector::max_size inplace_vector::capacity inplace_vector::resize inplace_vector::reserve inplace_vector::shrink_to_fit Iterators inplace_vector::begininplace_vector::cbegin inplace_vector::endinplace_vector::cend inplace_vector::rbegininplace_vector::crbegin inplace_vector::rendinplace_vector::crend	Element access inplace_vector::at inplace_vector::operator[] inplace_vector::front inplace_vector::back inplace_vector::data Modifiers inplace_vector::clear inplace_vector::erase inplace_vector::swap inplace_vector::insert inplace_vector::insert_range inplace_vector::emplace inplace_vector::emplace_back inplace_vector::try_emplace_back inplace_vector::unchecked_emplace_back inplace_vector::push_back inplace_vector::try_push_back inplace_vector::unchecked_push_back inplace_vector::pop_back inplace_vector::append_range inplace_vector::try_append_range
Non-member functions
erase(std::inplace_vector)erase_if(std::inplace_vector) swap(std::inplace_vector)	operator==operator<=>

 

Defined in header <inplace_vector>
template<class T, std::size_t N, class U = T > constexprtypenamestd::inplace_vector<T, N>::size_type     erase(std::inplace_vector<T, N>& c, const U& value );	(1)	(since C++26)
template<class T, std::size_t N, class Pred > constexprtypenamestd::inplace_vector<T, N>::size_type     erase_if(std::inplace_vector<T, N>& c, Pred pred );	(2)	(since C++26)

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

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

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). ​

Return value

The number of erased elements.

Complexity

Linear.

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 ommitedstd::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)]

See also

removeremove_if	removes elements satisfying specific criteria (function template)
ranges::removeranges::remove_if (C++20)(C++20)	removes elements satisfying specific criteria (algorithm function object)