Search results
Results from the WOW.Com Content Network
In computer science, type conversion, [1] [2] type casting, [1] [3] type coercion, [3] and type juggling [4] [5] are different ways of changing an expression from one data type to another. An example would be the conversion of an integer value into a floating point value or its textual representation as a string, and vice versa.
Although static_cast conversions are checked at compile time to prevent obvious incompatibilities, no run-time type checking is performed that would prevent a cast between incompatible data types, such as pointers. A static_cast from a pointer to a class B to a pointer to a derived class D is ill-formed if B is an inaccessible or ambiguous base ...
In these languages, the typeof operator is the method for obtaining run-time type information. In other languages, such as C# [2] or D [3] and, to some degree, in C (as part of nonstandard extensions and proposed standard revisions), [4] [5] the typeof operator returns the static type of the operand. That is, it evaluates to the declared type ...
Some features of C++ that promote more type-safe code: The new operator returns a pointer of type based on operand, whereas malloc returns a void pointer. C++ code can use virtual functions and templates to achieve polymorphism without void pointers. Safer casting operators, such as dynamic cast that performs run-time type checking.
In Object Pascal, RTTI can be used to perform safe type casts with the as operator, test the class to which an object belongs with the is operator, and manipulate type information at run time with classes contained in the RTTI unit [5] (i.e. classes: TRttiContext, TRttiInstanceType, etc.). In Ada, objects of tagged types also store a type tag ...
In class-based programming, downcasting, or type refinement, is the act of casting a base or parent class reference, to a more restricted derived class reference. [1] This is only allowable if the object is already an instance of the derived class, and so this conversion is inherently fallible.
C++ supports function, class, alias, and variable templates. Templates may be parameterized by types, compile-time constants, and other templates. Templates are implemented by instantiation at compile-time. To instantiate a template, compilers substitute specific arguments for a template's parameters to generate a concrete function or class ...
A related concept is inner types, also known as inner data type or nested type, which is a generalization of the concept of inner classes. C++ is an example of a language that supports both inner classes and inner types (via typedef declarations). [30] [31] A local class is a class defined within a procedure or function. Such structure limits ...