typedef float_least#_t, with
# replaced by the width, designates a floating-point type with a width of at least # bits, such that no floating-point
type with lesser size has at least the specified width. Thus,
float_least32_t denotes the smallest floating-point
type with a width of at least 32 bits.
Minimum-width floating-point types are provided for all existing exact-width floating-point types on a given platform.
For example, if a platform supports
will also be supported, etc.