Search results
Results from the WOW.Com Content Network
In C++, classes can be forward-declared if you only need to use the pointer-to-that-class type (since all object pointers are the same size, and this is what the compiler cares about). This is especially useful inside class definitions, e.g. if a class contains a member that is a pointer (or a reference) to another class.
C's offsetof() macro is an ANSI C library feature found in stddef.h. It evaluates to the offset (in bytes) of a given member within a struct or union type, an expression of type size_t . The offsetof() macro takes two parameters , the first being a structure or union name, and the second being the name of a subobject of the structure/union that ...
The enclosing class can be instantiated, rather a new derived class, which provides the definition of the method, would need to be created in order to create an instance of the class. Starting with Java 8, the lambda expression was included in the language, which could be viewed as a function declaration.
In C, variables with static storage duration that are not initialized explicitly are initialized to zero (or null, for pointers). [ 3 ] Not only are uninitialized variables a frequent cause of bugs, but this kind of bug is particularly serious because it may not be reproducible: for instance, a variable may remain uninitialized only in some ...
In some programming language environments (at least one proprietary Lisp implementation, for example), [citation needed] the value used as the null pointer (called nil in Lisp) may actually be a pointer to a block of internal data useful to the implementation (but not explicitly reachable from user programs), thus allowing the same register to be used as a useful constant and a quick way of ...
In C/C++ bitwise shifting a value by a number of bits which is either a negative number or is greater than or equal to the total number of bits in this value results in undefined behavior. The safest way (regardless of compiler vendor) is to always keep the number of bits to shift (the right operand of the << and >> bitwise operators ) within ...
In computer programming, a function prototype is a declaration of a function that specifies the function's name and type signature (arity, data types of parameters, and return type), but omits the function body. While a function definition specifies how the function does what it does (the "implementation"), a function prototype merely specifies ...
An undefined variable in the source code of a computer program is a variable that is accessed in the code but has not been declared by that code. [1] In some programming languages, an implicit declaration is provided the first time such a variable is encountered at compile time. In other languages such a usage is considered to be sufficiently ...