The unsigned integer types consist of:
The signed two's complement integer types consist of:
The IEEE 754-2008 "binary32" and "binary64" floating-point types are
Machine-dependent integer types
usize type is an unsigned integer type with the same number of bits as the
platform's pointer type. It can represent every memory address in the process.
isize type is a signed integer type with the same number of bits as the
platform's pointer type. The theoretical upper bound on object and array size
is the maximum
isize value. This ensures that
isize can be used to calculate
differences between pointers into an object or array and can address every byte
within an object along with one byte past the end.
isize are at least 16-bits wide.
Note: Many pieces of Rust code may assume that pointers,
isizeare either 32-bit or 64-bit. As a consequence, 16-bit pointer support is limited and may require explicit care and acknowledgment from a library to support.