library/core/tests/num/const_from.rs

   1 #[test]
   2 fn from() {
   3     use core::convert::TryFrom;
   4     use core::num::TryFromIntError;
   5
   6     // From
   7     const FROM: i64 = i64::from(1i32);
   8     assert_eq!(FROM, 1i64);
   9
  10     // From int to float
  11     const FROM_F64: f64 = f64::from(42u8);
  12     assert_eq!(FROM_F64, 42f64);
  13
  14     // Upper bounded
  15     const U8_FROM_U16: Result<u8, TryFromIntError> = u8::try_from(1u16);
  16     assert_eq!(U8_FROM_U16, Ok(1u8));
  17
  18     // Both bounded
  19     const I8_FROM_I16: Result<i8, TryFromIntError> = i8::try_from(1i16);
  20     assert_eq!(I8_FROM_I16, Ok(1i8));
  21
  22     // Lower bounded
  23     const I16_FROM_U16: Result<i16, TryFromIntError> = i16::try_from(1u16);
  24     assert_eq!(I16_FROM_U16, Ok(1i16));
  25 }