Crate sign_bound 

sign-bound

Signed integer types for Rust that are bounded to be either positive or negative. The API is analogous to the built-in NonZero types. The types are all memory-layout optimized, so for example Option<PositiveI32> and Option<NegativeI32> are both the same size as i32. Using additional variants in an enum can also have some space benefits.

enum MyEnum {
    A(PositiveI16),
    B,
    C,
    D,
}
assert_eq!(size_of::<MyEnum>(), size_of::<PositiveI16>());

Note that due to the implementation details of this crate, the space optimization for any type will not occur if there are more than 128 additional enum variants.

Option<PositiveIsize> is particularly useful as a space-efficient optional Vec index, since Rust’s Vec structure is limited to isize::MAX entries.

Macros

negative_i8

Creates a NegativeI8 checked at compile time.

negative_i16

Creates a NegativeI16 checked at compile time.

negative_i32

Creates a NegativeI32 checked at compile time.

negative_i64

Creates a NegativeI64 checked at compile time.

negative_isize

Creates a NegativeIsize checked at compile time.

positive_i8

Creates a PositiveI8 checked at compile time.

positive_i16

Creates a PositiveI16 checked at compile time.

positive_i32

Creates a PositiveI32 checked at compile time.

positive_i64

Creates a PositiveI64 checked at compile time.

positive_isize

Creates a PositiveIsize checked at compile time.

Structs

NegativeI8

A signed value that is known to be negative.

NegativeI16

A signed value that is known to be negative.

NegativeI32

A signed value that is known to be negative.

NegativeI64

A signed value that is known to be negative.

NegativeIsize

A signed value that is known to be negative.

PositiveI8

A signed value that is known to be positive.

PositiveI16

A signed value that is known to be positive.

PositiveI32

A signed value that is known to be positive.

PositiveI64

A signed value that is known to be positive.

PositiveIsize

A signed value that is known to be positive.