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| Deduction guides(C++17) | ||||||
size_type max_size()constnoexcept; | (since C++11) (constexpr since C++26) | |
Returns the maximum number of elements the container is able to hold due to system or library implementation limitations, i.e.std::distance(begin(), end()) for the largest container.
Contents |
Maximum number of elements.
Constant.
This value typically reflects the theoretical limit on the size of the container, at moststd::numeric_limits<difference_type>::max(). At runtime, the size of the container may be limited to a value smaller thanmax_size() by the amount of RAM available.
#include <iostream>#include <locale>#include <unordered_set> int main(){std::unordered_set<char> p;std::unordered_set<long> q; std::cout.imbue(std::locale("en_US.UTF-8"));std::cout<<std::uppercase<<"p.max_size() = "<<std::dec<< p.max_size()<<" = 0x"<<std::hex<< p.max_size()<<'\n'<<"q.max_size() = "<<std::dec<< q.max_size()<<" = 0x"<<std::hex<< q.max_size()<<'\n';}
Possible output:
p.max_size() = 1,152,921,504,606,846,975 = 0xFFF,FFF,FFF,FFF,FFFq.max_size() = 1,152,921,504,606,846,975 = 0xFFF,FFF,FFF,FFF,FFF
| returns the number of elements (public member function)[edit] |
