数字类型

Integer types

The unsigned integer types consist of:

Type Minimum Maximum
u8 0 28-1
u16 0 216-1
u32 0 232-1
u64 0 264-1
u128 0 2128-1

The signed two's complement integer types consist of:

Type Minimum Maximum
i8 -(27) 27-1
i16 -(215) 215-1
i32 -(231) 231-1
i64 -(263) 263-1
i128 -(2127) 2127-1

Floating-point types

The IEEE 754-2008 "binary32" and "binary64" floating-point types are f32 and f64, respectively.

Machine-dependent integer types

The 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.

The 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.