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An exception is Microsoft Visual C++ for x86, which makes long double a synonym for double. [2] The Intel C++ compiler on Microsoft Windows supports extended precision, but requires the /Qlong‑double switch for long double to correspond to the hardware's extended precision format. [3] Compilers may also use long double for the IEEE 754 ...
In computer science, boxing (a.k.a. wrapping) is the transformation of placing a primitive type within an object so that the value can be used as a reference. Unboxing is the reverse transformation of extracting the primitive value from its wrapper object.
The std::string class is the standard representation for a text string since C++98. The class provides some typical string operations like comparison, concatenation, find and replace, and a function for obtaining substrings. An std::string can be constructed from a C-style string, and a C-style string can also be obtained from one. [7]
In C and C++ short, long, and long long types are required to be at least 16, 32, and 64 bits wide, respectively, but can be more. The int type is required to be at least as wide as short and at most as wide as long , and is typically the width of the word size on the processor of the machine (i.e. on a 32-bit machine it is often 32 bits wide ...
A basic example is in the argv argument to the main function in C (and C++), which is given in the prototype as char **argv—this is because the variable argv itself is a pointer to an array of strings (an array of arrays), so *argv is a pointer to the 0th string (by convention the name of the program), and **argv is the 0th character of the ...
C++14 allows the creation of variables that are templated. An example given in the proposal is a variable pi that can be read to get the value of pi for various types (e.g., 3 when read as an integral type; the closest value possible with float, double or long double precision when read as float, double or long double, respectively; etc.).
On x86 and x86-64, the most common C/C++ compilers implement long double as either 80-bit extended precision (e.g. the GNU C Compiler gcc [13] and the Intel C++ Compiler with a /Qlong‑double switch [14]) or simply as being synonymous with double precision (e.g. Microsoft Visual C++ [15]), rather than as quadruple precision.
A string is defined as a contiguous sequence of code units terminated by the first zero code unit (often called the NUL code unit). [1] This means a string cannot contain the zero code unit, as the first one seen marks the end of the string. The length of a string is the number of code units before the zero code unit. [1]