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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.
The Boost C++ Libraries provide a dynamic_bitset class [4] whose size is specified at run-time. The D programming language provides bit arrays in its standard library, Phobos, in std.bitmanip. As in C++, the [] operator does not return a reference, since individual bits are not directly addressable on most hardware, but instead returns a bool.
Bit fields can be used to reduce memory consumption when a program requires a number of integer variables which always will have low values. For example, in many systems, storing an integer value requires two bytes (16-bits) of memory; sometimes the values to be stored actually need only one or two bits.
In addition to the assumption about bit-representation of floating-point numbers, the above floating-point type-punning example also violates the C language's constraints on how objects are accessed: [3] the declared type of x is float but it is read through an expression of type unsigned int.
Information about the actual properties, such as size, of the basic arithmetic types, is provided via macro constants in two headers: <limits.h> header (climits header in C++) defines macros for integer types and <float.h> header (cfloat header in C++) defines macros for floating-point types. The actual values depend on the implementation.
For unsigned integers, the bitwise complement of a number is the "mirror reflection" of the number across the half-way point of the unsigned integer's range. For example, for 8-bit unsigned integers, NOT x = 255 - x , which can be visualized on a graph as a downward line that effectively "flips" an increasing range from 0 to 255, to a ...
The actual sizes of short int, int, and long int are available as the constants short max int, max int, and long max int etc. ^b Commonly used for characters. ^c The ALGOL 68, C and C++ languages do not specify the exact width of the integer types short , int , long , and ( C99 , C++11 ) long long , so they are implementation-dependent.
HipHop for PHP (HPHPc) is a discontinued PHP transpiler created by Facebook. By using HPHPc as a source-to-source compiler , PHP code is translated into C++ , compiled into a binary and run as an executable , as opposed to the PHP's usual execution path of PHP code being transformed into opcodes and interpreted .