Build rand without default features (no_std)

The tests using rand/std have been moved to ci/big_rand/.

.travis.yml

@@ -26,7 +26,7 @@ matrix:
       before_script:
         - rustup target add $TARGET
       script:
-        - cargo build --verbose --target $TARGET --no-default-features --features "serde"
+        - cargo build --verbose --target $TARGET --no-default-features --features "serde rand"
     - name: "rustfmt"
       rust: 1.31.0
       before_script:

Cargo.toml

@@ -48,7 +48,6 @@ features = ["i128"]
 optional = true
 version = "0.7"
 default-features = false
-features = ["std", "small_rng"]
 
 [dependencies.serde]
 optional = true
@@ -65,15 +64,6 @@ optional = true
 version = "0.9"
 default-features = false
 
-[dev-dependencies.rand_xorshift]
-version = "0.2.0"
-
-[dev-dependencies.rand_chacha]
-version = "0.2.0"
-
-[dev-dependencies.rand_isaac]
-version = "0.2.0"
-
 [features]
 default = ["std"]
 std = ["num-integer/std", "num-traits/std"]

ci/big_rand/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "big_rand"
+version = "0.1.0"
+authors = ["Josh Stone <cuviper@gmail.com>"]
+
+[dependencies]
+num-traits = "0.2.11"
+rand_chacha = "0.2"
+rand_isaac = "0.2"
+rand_xorshift = "0.2"
+
+[dependencies.num-bigint]
+features = ["rand"]
+path = "../.."
+
+[dependencies.rand]
+features = ["small_rng"]
+version = "0.7"

tests/rand.rs → ci/big_rand/src/lib.rs

@@ -1,4 +1,10 @@
-#![cfg(feature = "rand")]
+//! Test randomization of `BigUint` and `BigInt`
+//!
+//! This test is in a completely separate crate so `rand::thread_rng()`
+//! can be available without "infecting" the rest of the build with
+//! `rand`'s default features, especially not `rand/std`.
+
+#![cfg(test)]
 
 extern crate num_bigint;
 extern crate num_traits;
@@ -7,9 +13,11 @@ extern crate rand_chacha;
 extern crate rand_isaac;
 extern crate rand_xorshift;
 
+mod torture;
+
 mod biguint {
     use num_bigint::{BigUint, RandBigInt, RandomBits};
-    use num_traits::Zero;
+    use num_traits::{Pow, Zero};
     use rand::distributions::Uniform;
     use rand::thread_rng;
     use rand::{Rng, SeedableRng};
@@ -162,6 +170,44 @@ mod biguint {
         use rand_xorshift::XorShiftRng;
         seeded_value_stability::<XorShiftRng>(EXPECTED);
     }
+
+    #[test]
+    fn test_roots_rand() {
+        fn check<T: Into<BigUint>>(x: T, n: u32) {
+            let x: BigUint = x.into();
+            let root = x.nth_root(n);
+            println!("check {}.nth_root({}) = {}", x, n, root);
+
+            if n == 2 {
+                assert_eq!(root, x.sqrt())
+            } else if n == 3 {
+                assert_eq!(root, x.cbrt())
+            }
+
+            let lo = root.pow(n);
+            assert!(lo <= x);
+            assert_eq!(lo.nth_root(n), root);
+            if !lo.is_zero() {
+                assert_eq!((&lo - 1u32).nth_root(n), &root - 1u32);
+            }
+
+            let hi = (&root + 1u32).pow(n);
+            assert!(hi > x);
+            assert_eq!(hi.nth_root(n), &root + 1u32);
+            assert_eq!((&hi - 1u32).nth_root(n), root);
+        }
+
+        let mut rng = thread_rng();
+        let bit_range = Uniform::new(0, 2048);
+        let sample_bits: Vec<_> = rng.sample_iter(&bit_range).take(100).collect();
+        for bits in sample_bits {
+            let x = rng.gen_biguint(bits);
+            for n in 2..11 {
+                check(x.clone(), n);
+            }
+            check(x.clone(), 100);
+        }
+    }
 }
 
 mod bigint {
@@ -324,4 +370,22 @@ mod bigint {
         use rand_xorshift::XorShiftRng;
         seeded_value_stability::<XorShiftRng>(EXPECTED);
     }
+
+    #[test]
+    fn test_random_shr() {
+        use rand::distributions::Standard;
+        use rand::Rng;
+        let rng = rand::thread_rng();
+
+        for p in rng.sample_iter::<i64, _>(&Standard).take(1000) {
+            let big = BigInt::from(p);
+            let bigger = &big << 1000;
+            assert_eq!(&bigger >> 1000, big);
+            for i in 0..64 {
+                let answer = BigInt::from(p >> i);
+                assert_eq!(&big >> i, answer);
+                assert_eq!(&bigger >> (1000 + i), answer);
+            }
+        }
+    }
 }

tests/torture.rs → ci/big_rand/src/torture.rs

@@ -1,9 +1,3 @@
-#![cfg(feature = "rand")]
-
-extern crate num_bigint;
-extern crate num_traits;
-extern crate rand;
-
 use num_bigint::RandBigInt;
 use num_traits::Zero;
 use rand::prelude::*;

ci/test_full.sh

@@ -12,7 +12,7 @@ esac
 
 case "$TRAVIS_RUST_VERSION" in
   1.3[1-5].*) ;;
-  *) NO_STD_FEATURES="serde" ;;
+  *) NO_STD_FEATURES="serde rand" ;;
 esac
 
 # num-bigint should build and test everywhere.
@@ -55,5 +55,6 @@ if [[ "$TRAVIS_RUST_VERSION" == "nightly" ]]; then
 fi
 
 case "$STD_FEATURES" in
-  *serde*) cargo test --manifest-path ci/big_serde/Cargo.toml
+  *serde*) cargo test --manifest-path ci/big_serde/Cargo.toml ;;&
+  *rand*) cargo test --manifest-path ci/big_rand/Cargo.toml ;;&
 esac

src/lib.rs

@@ -46,14 +46,11 @@
 //!
 //! It's easy to generate large random numbers:
 //!
-//! ```rust
-//! # #[cfg(feature = "rand")]
+//! ```rust,ignore
 //! extern crate rand;
-//! extern crate num_bigint as bigint;
+//! extern crate num_bigint;
 //!
-//! # #[cfg(feature = "rand")]
-//! # fn main() {
-//! use bigint::{ToBigInt, RandBigInt};
+//! use num_bigint::{ToBigInt, RandBigInt};
 //!
 //! let mut rng = rand::thread_rng();
 //! let a = rng.gen_bigint(1000);
@@ -64,11 +61,6 @@
 //!
 //! // Probably an even larger number.
 //! println!("{}", a * b);
-//! # }
-//!
-//! # #[cfg(not(feature = "rand"))]
-//! # fn main() {
-//! # }
 //! ```
 //!
 //! See the "Features" section for instructions for enabling random number generation.

tests/bigint.rs

@@ -1,8 +1,6 @@
 extern crate num_bigint;
 extern crate num_integer;
 extern crate num_traits;
-#[cfg(feature = "rand")]
-extern crate rand;
 
 use num_bigint::BigUint;
 use num_bigint::Sign::{Minus, NoSign, Plus};
@@ -1083,25 +1081,6 @@ fn test_negative_shr() {
     assert_eq!(BigInt::from(-3) >> 2, BigInt::from(-1));
 }
 
-#[test]
-#[cfg(feature = "rand")]
-fn test_random_shr() {
-    use rand::distributions::Standard;
-    use rand::Rng;
-    let rng = rand::thread_rng();
-
-    for p in rng.sample_iter::<i64, _>(&Standard).take(1000) {
-        let big = BigInt::from(p);
-        let bigger = &big << 1000;
-        assert_eq!(&bigger >> 1000, big);
-        for i in 0..64 {
-            let answer = BigInt::from(p >> i);
-            assert_eq!(&big >> i, answer);
-            assert_eq!(&bigger >> (1000 + i), answer);
-        }
-    }
-}
-
 #[test]
 fn test_iter_sum() {
     let result: BigInt = FromPrimitive::from_isize(-1234567).unwrap();

tests/roots.rs

@@ -2,9 +2,6 @@ extern crate num_bigint;
 extern crate num_integer;
 extern crate num_traits;
 
-#[cfg(feature = "rand")]
-extern crate rand;
-
 mod biguint {
     use num_bigint::BigUint;
     use num_traits::{One, Pow, Zero};
@@ -101,25 +98,6 @@ mod biguint {
         assert!(x.nth_root(u32::MAX).is_one());
     }
 
-    #[cfg(feature = "rand")]
-    #[test]
-    fn test_roots_rand() {
-        use num_bigint::RandBigInt;
-        use rand::distributions::Uniform;
-        use rand::{thread_rng, Rng};
-
-        let mut rng = thread_rng();
-        let bit_range = Uniform::new(0, 2048);
-        let sample_bits: Vec<_> = rng.sample_iter(&bit_range).take(100).collect();
-        for bits in sample_bits {
-            let x = rng.gen_biguint(bits);
-            for n in 2..11 {
-                check(x.clone(), n);
-            }
-            check(x.clone(), 100);
-        }
-    }
-
     #[test]
     fn test_roots_rand1() {
         // A random input that found regressions