std::forward_list assign() method

since C++11

// (1) Non const version only
void assign( size_type count, const T& value );

// (2) Non const version only
template< class InputIt >
void assign( InputIt first, InputIt last );

// (3) Non const version only
void assign( std::initializer_list<T> ilist );

Replaces the contents of the container with the contents of another.

• (1) Replaces the contents with count copies of value value.

• (2) Replaces the contents with copies of those in the range [ first, last ).

  Undefined Behavior

  The behavior is undefined

  if either argument is an iterator into *this.

  since C++11

  This overload participates in overload resolution only if InputIt satisfies LegacyInputIterator.

  until C++11

  This overload has the same effect as overload (1) if InputIt is an integral type.

• (3) Replaces the contents with the elements from the initializer list ilist.

Invalidation

All iterators, pointers and references to the elements of the container are invalidated.

Parameters

• count - the new size of the container
• value - the value to initialize elements of the container with
• first, last - the range to copy the elements from
• ilist - initializer list to copy the values from

Return value

(none)

Complexity

• (1) Linear in count - O(count).
• (2) Linear in distance between first and last - O(std::distance(first, last)).
• (3) Linear in ilist.size() - O(ilist.size()).

Exceptions

(none)

Examples

Main.cpp

#include <forward_list>
#include <iostream>
#include <string>

int main()
{
    std::forward_list<char> characters;

    auto print_forward_list = [&](){
        for (char c : characters)
            std::cout << c << ' ';
        std::cout << '\n';
    };

    characters.assign(5, 'a');
    print_forward_list();

    const std::string extra(6, 'b');
    characters.assign(extra.begin(), extra.end());
    print_forward_list();

    characters.assign({'C', '+', '+', '1', '1'});
    print_forward_list();
}

Output

a a a a a
b b b b b b
C + + 1 1