C++ to Rust

C++	Rust	Note
char	`u8/i8`	`char`s in C++ can be signed or unsigned. This assumption here is signed but it depends on the target system. `char` in Rust is not the same is C/C++ char since it supports all Unicode characters.
`unsigned char`	`u8`
`short`	`i16`
`unsigned short`	`u16`
`int`	`i32`	Assumed signed (C/C++)
`unsigned int`	`u32`	Assumed signed (C/C++)
`long`	`i64`	Assumed signed (C/C++)
`unsigned long`	`u32` or `u64`	Assumed signed (C/C++)
`long long int`	`i64`
`unsigned long long int`	`u64`
`size_t`	`usize`
`float`	`float32`
`double`	`f64`
`long double`	~~`f128`~~	`f128` support exists in Rust but was removed due to issues for some platforms supporting/implementing it.
`bool`	`bool`
`void`	`()`
`char32_t`	`char`
`wchar_t`	`u8`

stdint/cstdint types

For more detail, see this blog post. (Which isn't by me)

C#	Rust	Note
`sbyte`	`u8`
`byte`	`i8`
`short`	`i16`
`char`	`u16`	Rust `char` != C# `char`
`ushort`	`u16`
`int`	`i32`
`uint`	`u32`
`long`	`i64`
`ulong`	`u64`
N/A	`i128`	Does not exist natively in C#
N/A	`u128`	Does not exist natively in C#
`float`	`f32`
`double`	`f64`
`decimal`	`f128`	(Rust) Not supported on all platforms.