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std::ranges::common_range

Defined in header <ranges> 
template< class T >
  concept common_range =
    ranges::range<T> && std::same_as<ranges::iterator_t<T>, ranges::sentinel_t<T>>;
 (since C++20)

The common_range concept is a refinement of range for which std::ranges::begin() and std::ranges::end() return the same type (e.g. all standard library containers).

Example

#include <ranges>
 
struct A {
    char* begin();
    char* end();
};
static_assert( std::ranges::common_range<A> );
 
struct B {
    char* begin();
    bool end();
};  // not a common_range: begin/end have different types
static_assert( not std::ranges::common_range<B> );
 
struct C {
    char* begin();
};  // not a common_range, not even a range: has no end()
static_assert( not std::ranges::common_range<C> );
 
int main() { }

See also

(C++20)
converts a view into a common_range
(class template) (range adaptor object)

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https://en.cppreference.com/w/cpp/ranges/common_range