Is there a 128 bit integer in C++?

c++ performance types cross-platform uuid
danijar picture danijar · Aug 26, 2013 · Viewed 72.8k times · Source

I need to store a 128 bits long UUID in a variable. Is there a 128-bit datatype in C++? I do not need arithmetic operations, I just want to easily store and read the value very fast.

A new feature from C++11 would be fine, too.

Answer

Onkar picture Onkar · Jan 27, 2016

Although GCC does provide __int128, it is supported only for targets (processors) which have an integer mode wide enough to hold 128 bits. On a given system, sizeof() intmax_t and uintmax_t determine the maximum value that the compiler and the platform support.

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