int
may be as small as 16 bits on some platforms. It may not be sufficient for your application.uint32_t
is not guaranteed to exist. It’s an optionaltypedef
that the implementation must provide iff it has an unsigned integer type of exactly 32-bits. Some have a 9-bit bytes for example, so they don’t have auint32_t
.uint_fast32_t
states your intent clearly: it’s a type of at least 32 bits which is the best from a performance point-of-view.uint_fast32_t
may be in fact 64 bits long. It’s up to the implementation.- There’s also
uint_least32_t
in the mix. It designates the smallest type that’s at least 32 bits long, thus it can be smaller thanuint_fast32_t
. It’s an alternative touint32_t
if the later isn’t supported by the platform.
… there is
uint_fast32_t
which has the same typedef asuint32_t
…
What you are looking at is not the standard. It’s a particular implementation (BlackBerry). So you can’t deduce from there that uint_fast32_t
is always the same as uint32_t
.
See also: