std::array::empty
From cppreference.com
                    
                                        
                    
                    
                                                            
                    
| constexpr bool empty(); | (since C++11) (until C++14) | |
| constexpr bool empty() const; | (since C++14) | |
Checks if the container has no elements, i.e. whether begin() == end().
| Contents | 
[edit] Parameters
(none)
[edit] Return value
true if the container is empty, false otherwise
[edit] Exceptions
noexcept specification:  
noexcept
  [edit] Complexity
Constant.
[edit] Example
 The following code uses empty to check if a std::array contains any elements:
 
Run this code
#include <array> #include <iostream> int main() { std::array<int, 4> numbers {3, 1, 4, 1}; std::array<int, 0> no_numbers; std::cout << "numbers.empty(): " << numbers.empty() << '\n'; std::cout << "no_numbers.empty(): " << no_numbers.empty() << '\n'; }
Output:
numbers.empty(): 0 no_numbers.empty(): 1
See also
| returns the number of elements (public member function) | 


