public member function
<list>
std::list::empty
bool empty() const noexcept;
Test whether container is empty
Returns whether the list container is empty (i.e. whether its size is 0).
This function does not modify the container in any way. To clear the content of a list container, see list::clear.
Return Value
true if the container size is 0, false otherwise.
Example
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// list::empty
#include <iostream>
#include <list>
int main ()
{
std::list<int> mylist;
int sum (0);
for (int i=1;i<=10;++i) mylist.push_back(i);
while (!mylist.empty())
{
sum += mylist.front();
mylist.pop_front();
}
std::cout << "total: " << sum << '\n';
return 0;
}
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The example initializes the content of the container to a sequence of numbers (form 1 to 10). It then pops the elements one by one until it is empty and calculates their sum.
Output:
Iterator validity
No changes.
Data races
The container is accessed.
No contained elements are accessed: concurrently accessing or modifying them is safe.
Exception safety
No-throw guarantee: this member function never throws exceptions.