uintfast64t

uintfast64_t is a data type defined in the C programming language, specifically in the C99 standard and later. It is part of the stdint.h header, which provides a set of typedefs that specify exact-width integer types, as well as types that can hold integer values of at least a specified width.

uintfast64_t is an unsigned integer type that is at least 64 bits wide. The exact width of uintfast64_t may vary depending on the platform and compiler, but it will always be at least 64 bits. This type is intended to provide the fastest type that can hold at least 64 bits, which can be useful for performance-critical applications where the exact width is less important than the speed of operations.

The uintfast64_t type is not guaranteed to be the same size on all platforms. For example, on a 32-bit system, uintfast64_t might be a 64-bit type, while on a 64-bit system, it might be a 64-bit type as well. However, on a 128-bit system, it might be a 128-bit type.

uintfast64_t is useful in situations where a large integer type is needed, but the exact size is not critical. It is commonly used in low-level programming, such as system programming, embedded systems, and performance-critical applications. However, it should be used with caution, as the exact size and behavior of uintfast64_t can vary between platforms and compilers.