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| Linkage Specification C and C++ Recapitulation |
When a function name is changed by the compiler for unique identification at run-time, the process is known as name decoration or name mangling.
Linking happens after compilation. Inline functions are processed by the compiler, whereas non-inline functions are processed at run-time.
• C++ functions are similar to C functions. The functions,
such as calling, returning, and executing, work in the
same manner and the stack is involved in the same way
as in C.• C++ provides an inline function. This function call
is expanded like a macro. Inline functions are very
efficient and solve the problems associated with the
macros of C. However, it is not possible to make all
functions inline.• It is possible for the arguments to have a default value in
C++. The default arguments, if any, must be preceded
by all the normal arguments in the argument list.• Functions in C++ can receive as arguments and return
objects additionally.• It is possible to pass a reference and return a reference
from a C++ function.• When a C++ function returns a reference, it can be
on the RHS of an assignment statement. Function
prototype is compulsory in C++ when the function is
used before the definition.• It is also possible to overload a function with the same
name but different numbers of arguments or different
types of arguments in C++. This is known as function
overloading.• A C++ function can be defined as a member function of
some class or a non-member function.• It requires critical introspection to decide whether to make a function a member or a non-member.• It is also possible to declare a function as a friend of
some class. In such a case, the function that is not the
member of the specific class will be able to access the
private members of the class.• Like const and volatile variables, we can have const
and volatile objects in C++. A function can also be a
const or a volatile function.• A const function cannot alter the value of a data member
except for the ones defined as mutable.• Functions can also be defined as static. These functions
are not exactly member functions of a class. They
can only work with static data members of the class.
Usually, these functions are public.• A pointer to a non-member function is similar to a
function pointer in C. It is also possible to defi ne a
function pointer to a function member in C++. They are
very useful in making the program more flexible.• It is possible for a C++ program to use a compiled C
function from some library. We need to have a C linkage
specification for such functions.• A normal C function in its compiled form is different
from a C++ function because the C++ function is name
mangled whereas a C function is not. Thus, a function
when compiled as a C function generates a different object
code than when the same function is compiled as a C++
function.