src/librustc/util/num.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 pub trait ToPrimitive {
  12     fn to_i8(&self) -> Option<i8>;
  13     fn to_i16(&self) -> Option<i16>;
  14     fn to_i32(&self) -> Option<i32>;
  15     fn to_i64(&self) -> Option<i64>;
  16     fn to_u8(&self) -> Option<u8>;
  17     fn to_u16(&self) -> Option<u16>;
  18     fn to_u32(&self) -> Option<u32>;
  19     fn to_u64(&self) -> Option<u64>;
  20 }
  21
  22 impl ToPrimitive for i64 {
  23     fn to_i8(&self) -> Option<i8> {
  24         if *self < i8::min_value() as i64 || *self > i8::max_value() as i64 {
  25             None
  26         } else {
  27             Some(*self as i8)
  28         }
  29     }
  30     fn to_i16(&self) -> Option<i16> {
  31         if *self < i16::min_value() as i64 || *self > i16::max_value() as i64 {
  32             None
  33         } else {
  34             Some(*self as i16)
  35         }
  36     }
  37     fn to_i32(&self) -> Option<i32> {
  38         if *self < i32::min_value() as i64 || *self > i32::max_value() as i64 {
  39             None
  40         } else {
  41             Some(*self as i32)
  42         }
  43     }
  44     fn to_i64(&self) -> Option<i64> {
  45         Some(*self)
  46     }
  47     fn to_u8(&self) -> Option<u8> {
  48         if *self < 0 || *self > u8::max_value() as i64 {
  49             None
  50         } else {
  51             Some(*self as u8)
  52         }
  53     }
  54     fn to_u16(&self) -> Option<u16> {
  55         if *self < 0 || *self > u16::max_value() as i64 {
  56             None
  57         } else {
  58             Some(*self as u16)
  59         }
  60     }
  61     fn to_u32(&self) -> Option<u32> {
  62         if *self < 0 || *self > u32::max_value() as i64 {
  63             None
  64         } else {
  65             Some(*self as u32)
  66         }
  67     }
  68     fn to_u64(&self) -> Option<u64> {
  69         if *self < 0 {None} else {Some(*self as u64)}
  70     }
  71 }
  72
  73 impl ToPrimitive for u64 {
  74     fn to_i8(&self) -> Option<i8> {
  75         if *self > i8::max_value() as u64 {None} else {Some(*self as i8)}
  76     }
  77     fn to_i16(&self) -> Option<i16> {
  78         if *self > i16::max_value() as u64 {None} else {Some(*self as i16)}
  79     }
  80     fn to_i32(&self) -> Option<i32> {
  81         if *self > i32::max_value() as u64 {None} else {Some(*self as i32)}
  82     }
  83     fn to_i64(&self) -> Option<i64> {
  84         if *self > i64::max_value() as u64 {None} else {Some(*self as i64)}
  85     }
  86     fn to_u8(&self) -> Option<u8> {
  87         if *self > u8::max_value() as u64 {None} else {Some(*self as u8)}
  88     }
  89     fn to_u16(&self) -> Option<u16> {
  90         if *self > u16::max_value() as u64 {None} else {Some(*self as u16)}
  91     }
  92     fn to_u32(&self) -> Option<u32> {
  93         if *self > u32::max_value() as u64 {None} else {Some(*self as u32)}
  94     }
  95     fn to_u64(&self) -> Option<u64> {
  96         Some(*self)
  97     }
  98 }