cpp/utility/pair/get

Extracts an element from the pair using interface.

@1-4@ The index-based overloads fail to compile if the index is neither  nor.

@5-12@ The type-based overloads fail to compile if the types and  are the same.

Return value
@1-4@ Returns a reference to if  and a reference to  if. @5-8@ Returns a reference to. @9-12@ Returns a reference to.