public member function
<array>
std::array::empty
constexpr bool empty() noexcept;
Test whether array is empty
Returns a bool value indicating whether the array container is empty, i.e. whether its size is 0.
This function does not modify the content of the array in any way. To clear the content of an array object, use array::fill.
Return Value
true if the array size is 0, false otherwise.
This is a constexpr.
Example
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// array::empty
#include <iostream>
#include <array>
int main ()
{
std::array<int,0> first;
std::array<int,5> second;
std::cout << "first " << (first.empty() ? "is empty" : "is not empty") << '\n';
std::cout << "second " << (second.empty() ? "is empty" : "is not empty") << '\n';
return 0;
}
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Output:
first is empty
second is not empty
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Iterator validity
No changes.
Data races
No contained elements are accessed: concurrently accessing or modifying them is safe.
Exception safety
No-throw guarantee: this member function never throws exceptions.
See also
- array::fill
- Fill array with value (public member function)
- array::size
- Return size (public member function)