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

 

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std::span

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span::beginspan::cbegin (C++23)

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span::rbeginspan::crbegin (C++23)

span::rendspan::crend (C++23)

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span::empty

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span::size_bytes

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span::first

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span::subspan

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as_bytesas_writable_bytes

Non-member constant

dynamic_extent

Deduction guides

 

constexpr size_type size()constnoexcept;		(since C++20)

Returns the number of elements in the span.

Return value

The number of elements in the span.

Note

Feature-test macro	Value	Std	Feature
__cpp_lib_ssize	201902L	(C++20)	std::ssize and unsigned std::span::size

Example

Run this code

#include <span>   int main(){constexprstaticint c_array[]{1, 2, 3, 4, 5, 6, 7, 8};   constexprstd::span<constint> span{c_array};   static_assert(8== span.size()); static_assert(7== span.first(7).size()); static_assert(6== span.first<6>().size()); static_assert(5== span.last(5).size()); static_assert(4== span.last<4>().size()); static_assert(3== span.subspan(2, 3).size()); static_assert(2== span.subspan<3, 2>().size()); static_assert(1== span.subspan<7>().size());}

See also

(constructor)	constructs a span (public member function)
size_bytes	returns the size of the sequence in bytes (public member function)