std::span<T,Extent>::first

From cppreference.com
< cpp‎ | container‎ | span
template< std::size_t Count >
constexpr std::span<element_type, Count> first() const;
constexpr std::span<element_type, std::dynamic_extent> first( std::size_t Count ) const;

Obtains a span that is a view over the first Count elements of this span. The behavior is undefined if Count > size().

Return value

A span r that is a view over the first Count elements of *this, such that r.data() == this->data() && r.size() == Count.

See also

obtains a subspan consisting of the last N elements of the sequence
(public member function)
obtains a subspan
(public member function)