guint64

Guint64 is an unsigned 64-bit integer type provided by GLib. It is part of GLib’s fixed-width integer types, designed to be portable across the platforms GLib supports. The exact C type backing guint64 may vary (commonly unsigned long long or unsigned long), but code should rely on the guint64 typedef rather than the underlying type. The value range is 0 to 18,446,744,073,709,551,615 (2^64−1).

GLib uses guint64 in APIs that require large integers such as file sizes, time stamps, or unique identifiers. When formatting or printing guint64 values, GLib provides portable format specifiers, notably G_GUINT64_FORMAT, to be used with the printf family (for example: printf("%" G_GUINT64_FORMAT "\n", value)).

In terms of interoperability, guint64 corresponds to the C standard fixed-width type uint64_t when available, and GLib’s type system is designed to work across platforms and language bindings that rely on GLib. The signed counterpart of guint64 is gint64. Using guint64 in GLib-based code helps ensure consistent behavior across platforms and improves portability when interfacing with GLib APIs and bindings.