Search results
Results from the WOW.Com Content Network
C struct data types may end with a flexible array member [1] with no specified size: struct vectord { short len ; // there must be at least one other data member double arr []; // the flexible array member must be last // The compiler may reserve extra padding space here, like it can between struct members };
The C programming language provides many standard library functions for file input and output.These functions make up the bulk of the C standard library header <stdio.h>. [1] The functionality descends from a "portable I/O package" written by Mike Lesk at Bell Labs in the early 1970s, [2] and officially became part of the Unix operating system in Version 7.
array + 1 means 0x1004: the "+ 1" means to add the size of 1 int, which is 4 bytes; *array means to dereference the contents of array. Considering the contents as a memory address (0x1000), look up the value at that location (0x0002); array[i] means element number i, 0-based, of array which is translated into *(array + i).
sizeof can be used to determine the number of elements in an array, by dividing the size of the entire array by the size of a single element. This should be used with caution; When passing an array to another function, it will "decay" to a pointer type. At this point, sizeof will return the size of the pointer, not the total size of the array.
A limited number of later CPUs have specialised instructions for checking bounds, e.g., the CHK2 instruction on the Motorola 68000 series. Research has been underway since at least 2005 regarding methods to use x86's built-in virtual memory management unit to ensure safety of array and buffer accesses. [ 4 ]
The maximum size of size_t is provided via SIZE_MAX, a macro constant which is defined in the <stdint.h> header (cstdint header in C++). size_t is guaranteed to be at least 16 bits wide. Additionally, POSIX includes ssize_t , which is a signed integer type of the same width as size_t .
EDOM: A parameter was outside a function's domain, e.g. sqrt (-1) ERANGE: A result outside a function's range, e.g. strtol ("0xfffffffff", NULL, 0) on systems with a 32-bit wide long
Also, enumeration constants (enum enumerators) are always of type int in C, whereas they are distinct types in C++ and may have a size different from that of int. [needs update] In C++ a const variable must be initialized; in C this is not necessary. C++ compilers prohibit goto or switch from crossing an initialization, as in the following C99 ...