How does SFINAE work?
This rule applies during function template overload resolution: when substitution of the type specified or explicitly inferred by the template parameter fails, the specialization is discarded from the overload set rather than causing a compile error. This function is used in template metaprogramming.
Table of Contents
What does Decltype mean in C++?
In the C++ programming language, decltype is a keyword used to query the type of an expression. In general, the inferred type matches the type of the object or function exactly as declared in the source code. Like the sizeof operator, the decltype operand is not evaluated.
What does Typename do in C++?
“typename” is a keyword in the C++ programming language that is used when writing templates. Used to specify that a dependent name in a template declaration or definition is a type.
Is the integral of type C++?
std::is_integral All fundamental integral types, along with all their aliases (such as those for cstdint), are considered integral types by this class, including their const and volatile qualified variants. Enumerations are not considered integral types in C++ (see is_enum).
What does && mean in C++?
Comments. The logical AND operator (&&) returns true if both operands are true and returns false otherwise. The operands are implicitly converted to type bool before evaluation, and the result is of type bool.
What does Typeid C++ return?
typeid is a C++ language operator that returns type identification information at run time. Basically, it returns a type_info object, which is equal to other type_info objects.
What are the advantages of using templates in C++?
Advantages of Using Templates in C++
- Templates are type safe.
- They are generally considered an improvement over macros for these purposes.
- Templates avoid some common errors found in code that makes heavy use of function-like macros.
- Both templates and macros are expanded at compile time.
What does three dots mean in C++?
In our function declaration we have used ellipse (three dots); which means we can pass any number of arguments. C/C++ provides macros va_start, va_end, and va_arg to handle these arguments.
Is void a type?
Yes, void is a type.
What does void * mean and how is it used?
When used as a function return type, the void keyword specifies that the function does not return a value. When used for a function’s parameter list, void specifies that the function takes no parameters. When used in a pointer declaration, void specifies that the pointer is “universal”.
What is the main use of SFINAE in C++?
Before explaining what SFINAE is, let’s explore one of its main uses: introspection. As you may know, C++ doesn’t excel when it comes to examining the type or properties of an object at run time. The best capability provided by default would be RTTI.
Is the Genious is valid function a SFINAE function?
This cool is_valid function relies heavily on an even more “magical” C++ programming technique coined with the term SFINAE discovered at the turn of the last century. If these acronyms do not speak to you, do not be scared, we are going to get into the subject.
What is an example of the SFINAE concept?
The SFINAE concept simply guarantees such “sane” behavior for a “sane” compiler. For example: /* The compiler will test this overload as it is less generic than the variable.