Add support for 128-bit integers

.travis.yml

@@ -1,6 +1,7 @@
 language: rust
 rust:
   - 1.15.0
+  - 1.26.0
   - stable
   - beta
   - nightly

Cargo.toml

@@ -11,22 +11,24 @@ repository = "https://github.com/rust-num/num-rational"
 version = "0.2.0-git"
 publish = false
 readme = "README.md"
+build = "build.rs"
 
 [package.metadata.docs.rs]
-all-features = true
+features = ["std", "bigint-std", "serde"]
 
 [dependencies]
 
 [dependencies.num-bigint]
 optional = true
 version = "0.2.0"
+default-features = false
 
 [dependencies.num-integer]
-version = "0.1.36"
+version = "0.1.38"
 default-features = false
 
 [dependencies.num-traits]
-version = "0.2.1"
+version = "0.2.4"
 default-features = false
 
 [dependencies.serde]
@@ -35,6 +37,8 @@ version = "1.0.0"
 default-features = false
 
 [features]
-default = ["bigint", "std"]
-bigint = ["num-bigint", "std"]
-std = ["num-traits/std"]
+default = ["bigint-std", "std"]
+i128 = ["num-integer/i128", "num-traits/i128"]
+std = ["num-integer/std", "num-traits/std"]
+bigint = ["num-bigint"]
+bigint-std = ["bigint", "num-bigint/std"]

README.md

@@ -2,7 +2,7 @@
 
 [![crate](https://img.shields.io/crates/v/num-rational.svg)](https://crates.io/crates/num-rational)
 [![documentation](https://docs.rs/num-rational/badge.svg)](https://docs.rs/num-rational)
-![minimum rustc 1.8](https://img.shields.io/badge/rustc-1.8+-red.svg)
+![minimum rustc 1.15](https://img.shields.io/badge/rustc-1.15+-red.svg)
 [![Travis status](https://travis-ci.org/rust-num/num-rational.svg?branch=master)](https://travis-ci.org/rust-num/num-rational)
 
 Generic `Rational` numbers for Rust.
@@ -33,10 +33,14 @@ version = "0.2"
 default-features = false
 ```
 
+Implementations for `i128` and `u128` are only available with Rust 1.26 and
+later.  The build script automatically detects this, but you can make it
+mandatory by enabling the `i128` crate feature.
+
 ## Releases
 
 Release notes are available in [RELEASES.md](RELEASES.md).
 
 ## Compatibility
 
-The `num-rational` crate is tested for rustc 1.8 and greater.
+The `num-rational` crate is tested for rustc 1.15 and greater.

build.rs

@@ -0,0 +1,35 @@
+use std::env;
+use std::io::Write;
+use std::process::{Command, Stdio};
+
+fn main() {
+    if probe("fn main() { 0i128; }") {
+        println!("cargo:rustc-cfg=has_i128");
+    } else if env::var_os("CARGO_FEATURE_I128").is_some() {
+        panic!("i128 support was not detected!");
+    }
+}
+
+/// Test if a code snippet can be compiled
+fn probe(code: &str) -> bool {
+    let rustc = env::var_os("RUSTC").unwrap_or_else(|| "rustc".into());
+    let out_dir = env::var_os("OUT_DIR").expect("environment variable OUT_DIR");
+
+    let mut child = Command::new(rustc)
+        .arg("--out-dir")
+        .arg(out_dir)
+        .arg("--emit=obj")
+        .arg("-")
+        .stdin(Stdio::piped())
+        .spawn()
+        .expect("rustc probe");
+
+    child
+        .stdin
+        .as_mut()
+        .expect("rustc stdin")
+        .write_all(code.as_bytes())
+        .expect("write rustc stdin");
+
+    child.wait().expect("rustc probe").success()
+}

ci/rustup.sh

@@ -1,11 +1,11 @@
 #!/bin/sh
 # Use rustup to locally run the same suite of tests as .travis.yml.
-# (You should first install/update 1.15.0, stable, beta, and nightly.)
+# (You should first install/update all versions listed below.)
 
 set -ex
 
 export TRAVIS_RUST_VERSION
-for TRAVIS_RUST_VERSION in 1.15.0 stable beta nightly; do
+for TRAVIS_RUST_VERSION in 1.15.0 1.26.0 stable beta nightly; do
     run="rustup run $TRAVIS_RUST_VERSION"
     $run cargo build --verbose
     $run $PWD/ci/test_full.sh

ci/test_full.sh

@@ -4,6 +4,11 @@ set -ex
 
 echo Testing num-rational on rustc ${TRAVIS_RUST_VERSION}
 
+FEATURES="std bigint-std serde"
+if [[ "$TRAVIS_RUST_VERSION" =~ ^(nightly|beta|stable|1.26.0)$ ]]; then
+  FEATURES="$FEATURES i128"
+fi
+
 # num-rational should build and test everywhere.
 cargo build --verbose
 cargo test --verbose
@@ -13,7 +18,11 @@ cargo build --no-default-features
 cargo test --no-default-features
 
 # Each isolated feature should also work everywhere.
-for feature in bigint serde std; do
+for feature in $FEATURES; do
   cargo build --verbose --no-default-features --features="$feature"
   cargo test --verbose --no-default-features --features="$feature"
 done
+
+# test all supported features together
+cargo build --features="$FEATURES"
+cargo test --features="$FEATURES"

src/lib.rs

@@ -991,10 +991,20 @@ impl FromPrimitive for Ratio<BigInt> {
         Some(Ratio::from_integer(n.into()))
     }
 
+    #[cfg(has_i128)]
+    fn from_i128(n: i128) -> Option<Self> {
+        Some(Ratio::from_integer(n.into()))
+    }
+
     fn from_u64(n: u64) -> Option<Self> {
         Some(Ratio::from_integer(n.into()))
     }
 
+    #[cfg(has_i128)]
+    fn from_u128(n: u128) -> Option<Self> {
+        Some(Ratio::from_integer(n.into()))
+    }
+
     fn from_f32(n: f32) -> Option<Self> {
         Ratio::from_float(n)
     }
@@ -1011,10 +1021,20 @@ macro_rules! from_primitive_integer {
                 <$typ as FromPrimitive>::from_i64(n).map(Ratio::from_integer)
             }
 
+            #[cfg(has_i128)]
+            fn from_i128(n: i128) -> Option<Self> {
+                <$typ as FromPrimitive>::from_i128(n).map(Ratio::from_integer)
+            }
+
             fn from_u64(n: u64) -> Option<Self> {
                 <$typ as FromPrimitive>::from_u64(n).map(Ratio::from_integer)
             }
 
+            #[cfg(has_i128)]
+            fn from_u128(n: u128) -> Option<Self> {
+                <$typ as FromPrimitive>::from_u128(n).map(Ratio::from_integer)
+            }
+
             fn from_f32(n: f32) -> Option<Self> {
                 $approx(n, 10e-20, 30)
             }
@@ -1030,12 +1050,16 @@ from_primitive_integer!(i8, approximate_float);
 from_primitive_integer!(i16, approximate_float);
 from_primitive_integer!(i32, approximate_float);
 from_primitive_integer!(i64, approximate_float);
+#[cfg(has_i128)]
+from_primitive_integer!(i128, approximate_float);
 from_primitive_integer!(isize, approximate_float);
 
 from_primitive_integer!(u8, approximate_float_unsigned);
 from_primitive_integer!(u16, approximate_float_unsigned);
 from_primitive_integer!(u32, approximate_float_unsigned);
 from_primitive_integer!(u64, approximate_float_unsigned);
+#[cfg(has_i128)]
+from_primitive_integer!(u128, approximate_float_unsigned);
 from_primitive_integer!(usize, approximate_float_unsigned);
 
 impl<T: Integer + Signed + Bounded + NumCast + Clone> Ratio<T> {
@@ -1706,7 +1730,7 @@ mod test {
     #[cfg(feature = "bigint")]
     #[test]
     fn test_from_float_fail() {
-        use std::{f32, f64};
+        use core::{f32, f64};
 
         assert_eq!(Ratio::from_float(f32::NAN), None);
         assert_eq!(Ratio::from_float(f32::INFINITY), None);