rust/tests/compile-fail/cast.rs
R.Chavignat ad0bc66402 Added support for isize/usize in the CastPass lint pass.
Extracted the match that determines an integer types's size in a
utility function and implemented support for usize/isize.
Added a needed feature to the crate root.
Added some tests to cover those cases, and a test I previously forgot.
Silenced two errors signaled by dogfood.sh in unicode.rs.
2015-08-21 03:03:37 +02:00

57 lines
3.1 KiB
Rust

#![feature(plugin)]
#![plugin(clippy)]
#[deny(cast_precision_loss, cast_possible_truncation, cast_sign_loss)]
#[allow(dead_code)]
fn main() {
let i : i32 = 42;
let u : u32 = 42;
let f : f32 = 42.0;
// Test cast_precision_loss
i as f32; //~ERROR converting from i32 to f32, which causes a loss of precision (i32 is 32 bits wide, but f32's mantissa is only 23 bits wide)
(i as i64) as f32; //~ERROR converting from i64 to f32, which causes a loss of precision (i64 is 64 bits wide, but f32's mantissa is only 23 bits wide)
(i as i64) as f64; //~ERROR converting from i64 to f64, which causes a loss of precision (i64 is 64 bits wide, but f64's mantissa is only 52 bits wide)
u as f32; //~ERROR converting from u32 to f32, which causes a loss of precision (u32 is 32 bits wide, but f32's mantissa is only 23 bits wide)
(u as u64) as f32; //~ERROR converting from u64 to f32, which causes a loss of precision (u64 is 64 bits wide, but f32's mantissa is only 23 bits wide)
(u as u64) as f64; //~ERROR converting from u64 to f64, which causes a loss of precision (u64 is 64 bits wide, but f64's mantissa is only 52 bits wide)
i as f64; // Should not trigger the lint
u as f64; // Should not trigger the lint
// Test cast_possible_truncation
f as i32; //~ERROR casting f32 to i32 may cause truncation of the value
f as u32; //~ERROR casting f32 to u32 may cause truncation of the value
//~^ERROR casting from f32 to u32 loses the sign of the value
i as u8; //~ERROR casting i32 to u8 may cause truncation of the value
//~^ERROR casting from i32 to u8 loses the sign of the value
(f as f64) as f32; //~ERROR casting f64 to f32 may cause truncation of the value
i as i8; //~ERROR casting i32 to i8 may cause truncation of the value
u as i32; //~ERROR casting u32 to i32 may cause truncation of the value
// Test cast_sign_loss
i as u32; //~ERROR casting from i32 to u32 loses the sign of the value
// Extra checks for usize/isize
let is : isize = -42;
is as usize; //~ERROR casting from isize to usize loses the sign of the value
is as i8; //~ERROR casting isize to i8 may cause truncation of the value
// FIXME : enable these checks when we figure out a way to make compiletest deal with conditional compilation
/*
#[cfg(target_pointer_width = "64")]
fn check_64() {
let is : isize = -42;
let us : usize = 42;
is as f32; //ERROR converting from isize to f32, which causes a loss of precision (isize is 64 bits wide, but f32's mantissa is only 23 bits wide)
us as u32; //ERROR casting usize to u32 may cause truncation of the value
us as u64; // Should not trigger any lint
}
#[cfg(target_pointer_width = "32")]
fn check_32() {
let is : isize = -42;
let us : usize = 42;
is as f32; //ERROR converting from isize to f32, which causes a loss of precision (isize is 32 bits wide, but f32's mantissa is only 23 bits wide)
us as u32; // Should not trigger any lint
us as u64; // Should not trigger any lint
}*/
}