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What are the known shortfalls of const in C++ and C++0x?
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The const keyword specifies that a variable's value is constant and tells the compiler to prevent the programmer from modifying it. In C, constant values default to external linkage, so they can appear only in source files.
Const (constant) in programming is a keyword that defines a variable or pointer as unchangeable. A const may be applied in an object declaration to indicate that the object, unlike a standard variable, does not change. Such fixed values for objects are often termed literals.
The const declaration creates a read-only reference to a value. It does not mean the value it holds is immutable—just that the variable identifier cannot be reassigned. For instance, in the case where the content is an object, this means the object's contents (e.g., its properties) can be altered.
In C, C++, and D, all data types, including those defined by the user, can be declared const , and const-correctness dictates that all variables or objects should be declared as such unless they need to be modified.
It is perfectly legal for a compiler to deduce const for auto if it is not changing program functionality in any way. That also includes checks if there are const and non-const member functions available.
Constants refer to fixed values that the program may not alter and they are called literals. Constants can be of any of the basic data types and can be divided into Integer Numerals, Floating-Point Numerals, Characters, Strings and Boolean Values.
The only thing wrong with const is that it is seriously underrated by to many developers. It's one of the best tools in C++'s toolbox, very sharp, and yet not dangerous to cut yourself with.
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