std: Fill in all missing imports

Fallout from the previous commits

4 files changed, 9 insertions, 3 deletions

diff --git a/src/libstd/rand/distributions/exponential.rs b/src/libstd/rand/distributions/exponential.rs
index 6164ecd1a2b..fe1d8c505ca 100644
--- a/src/libstd/rand/distributions/exponential.rs
+++ b/src/libstd/rand/distributions/exponential.rs
@@ -10,6 +10,7 @@
 
 //! The exponential distribution.
 
+use num::Exponential;
 use rand::{Rng, Rand};
 use rand::distributions::{ziggurat, ziggurat_tables, Sample, IndependentSample};
 
diff --git a/src/libstd/rand/distributions/gamma.rs b/src/libstd/rand/distributions/gamma.rs
index 731baa0f305..78b6f5b8c7f 100644
--- a/src/libstd/rand/distributions/gamma.rs
+++ b/src/libstd/rand/distributions/gamma.rs
@@ -10,10 +10,11 @@
 
 //! The Gamma and derived distributions.
 
+use num::Algebraic;
+use num;
 use rand::{Rng, Open01};
-use super::{IndependentSample, Sample, Exp};
 use super::normal::StandardNormal;
-use num;
+use super::{IndependentSample, Sample, Exp};
 
 /// The Gamma distribution `Gamma(shape, scale)` distribution.
 ///
diff --git a/src/libstd/rand/distributions/mod.rs b/src/libstd/rand/distributions/mod.rs
index a297bbee1e6..e29a70aede9 100644
--- a/src/libstd/rand/distributions/mod.rs
+++ b/src/libstd/rand/distributions/mod.rs
@@ -20,11 +20,14 @@ that do not need to record state.
 
 */
 
-use iter::range;
+use container::Container;
+use iter::{range, Iterator};
 use option::{Some, None};
 use num;
+use num::CheckedAdd;
 use rand::{Rng, Rand};
 use clone::Clone;
+use vec::MutableVector;
 
 pub use self::range::Range;
 pub use self::gamma::{Gamma, ChiSquared, FisherF, StudentT};
diff --git a/src/libstd/rand/distributions/normal.rs b/src/libstd/rand/distributions/normal.rs
index 8dc9372aec9..7b24f78bdcf 100644
--- a/src/libstd/rand/distributions/normal.rs
+++ b/src/libstd/rand/distributions/normal.rs
@@ -10,6 +10,7 @@
 
 //! The normal and derived distributions.
 
+use num::Exponential;
 use rand::{Rng, Rand, Open01};
 use rand::distributions::{ziggurat, ziggurat_tables, Sample, IndependentSample};