c++ - What is decltype and how is it used? - Stack Overflow 153 decltype is a way to specify a type: You give it an expression, and decltype gives you back a type which corresponds to the type of the expression, as explained in [dcl type simple] p4: The type denoted by decltype(e) is defined as follows:
c++ - What are some uses of decltype (auto)? - Stack Overflow In c++14 the decltype (auto) idiom is introduced Typically its use is to allow auto declarations to use the decltype rules on the given expression Searching for examples of "good" usage of the
Is it possible to print (the name of) a variables type in standard C++? The former is the type of the declaration of i The latter is the "type" of the expression i (expressions never have reference type, but as a convention decltype represents lvalue expressions with lvalue references) Thus this tool is an excellent vehicle just to learn about decltype, in addition to exploring and debugging your own code
c++ - How do I use decltype to get the type instead of a reference to . . . Using decltype with operator* (AKA the indirection operator) indeed yields a reference type This is because operator* returns an "lvalue referring to the object", and decltype yields a T for lvalues ("if the value category of expression is lvalue, then decltype yields T ")