Use `const`s instead of `static`s where appropriate

This changes the type of some public constants/statics in libunicode.
Notably some `&'static &'static [(char, char)]` have changed
to `&'static [(char, char)]`. The regexp crate seems to be the
sole user of these, yet this is technically a [breaking-change]

11 files changed, 23 insertions, 24 deletions

diff --git a/src/libstd/net/tcp.rs b/src/libstd/net/tcp.rs
index f99cd2b1d1b..6ce3a939c6a 100644
--- a/src/libstd/net/tcp.rs
+++ b/src/libstd/net/tcp.rs
@@ -425,7 +425,7 @@ mod tests {
 
     #[test]
     fn multiple_connect_interleaved_lazy_schedule_ip4() {
-        static MAX: usize = 10;
+        const MAX: usize = 10;
         each_ip(&mut |addr| {
             let acceptor = t!(TcpListener::bind(&addr));
 
diff --git a/src/libstd/num/strconv.rs b/src/libstd/num/strconv.rs
index f6d05f961e1..90813fe7230 100644
--- a/src/libstd/num/strconv.rs
+++ b/src/libstd/num/strconv.rs
@@ -422,8 +422,8 @@ pub fn float_to_str_common<T: Float>(
 
 // Some constants for from_str_bytes_common's input validation,
 // they define minimum radix values for which the character is a valid digit.
-static DIGIT_P_RADIX: u32 = ('p' as u32) - ('a' as u32) + 11;
-static DIGIT_E_RADIX: u32 = ('e' as u32) - ('a' as u32) + 11;
+const DIGIT_P_RADIX: u32 = ('p' as u32) - ('a' as u32) + 11;
+const DIGIT_E_RADIX: u32 = ('e' as u32) - ('a' as u32) + 11;
 
 #[cfg(test)]
 mod tests {
diff --git a/src/libstd/rand/mod.rs b/src/libstd/rand/mod.rs
index 5c891441198..7fe20c37c6c 100644
--- a/src/libstd/rand/mod.rs
+++ b/src/libstd/rand/mod.rs
@@ -321,7 +321,7 @@ impl reseeding::Reseeder<StdRng> for ThreadRngReseeder {
         }
     }
 }
-static THREAD_RNG_RESEED_THRESHOLD: usize = 32_768;
+const THREAD_RNG_RESEED_THRESHOLD: usize = 32_768;
 type ThreadRngInner = reseeding::ReseedingRng<StdRng, ThreadRngReseeder>;
 
 /// The thread-local RNG.
@@ -639,18 +639,17 @@ mod test {
 }
 
 #[cfg(test)]
-static RAND_BENCH_N: u64 = 100;
-
-#[cfg(test)]
 mod bench {
     extern crate test;
     use prelude::v1::*;
 
     use self::test::Bencher;
-    use super::{XorShiftRng, StdRng, IsaacRng, Isaac64Rng, Rng, RAND_BENCH_N};
+    use super::{XorShiftRng, StdRng, IsaacRng, Isaac64Rng, Rng};
     use super::{OsRng, weak_rng};
     use mem::size_of;
 
+    const RAND_BENCH_N: u64 = 100;
+
     #[bench]
     fn rand_xorshift(b: &mut Bencher) {
         let mut rng: XorShiftRng = OsRng::new().unwrap().gen();
diff --git a/src/libstd/rand/os.rs b/src/libstd/rand/os.rs
index 1a13405633d..c2ead267578 100644
--- a/src/libstd/rand/os.rs
+++ b/src/libstd/rand/os.rs
@@ -281,9 +281,9 @@ mod imp {
         hcryptprov: HCRYPTPROV
     }
 
-    static PROV_RSA_FULL: DWORD = 1;
-    static CRYPT_SILENT: DWORD = 64;
-    static CRYPT_VERIFYCONTEXT: DWORD = 0xF0000000;
+    const PROV_RSA_FULL: DWORD = 1;
+    const CRYPT_SILENT: DWORD = 64;
+    const CRYPT_VERIFYCONTEXT: DWORD = 0xF0000000;
 
     #[allow(non_snake_case)]
     extern "system" {
diff --git a/src/libstd/sync/mpsc/mod.rs b/src/libstd/sync/mpsc/mod.rs
index 1310d476f8e..ee8bef50d89 100644
--- a/src/libstd/sync/mpsc/mod.rs
+++ b/src/libstd/sync/mpsc/mod.rs
@@ -1157,8 +1157,8 @@ mod test {
 
     #[test]
     fn stress_shared() {
-        static AMT: u32 = 10000;
-        static NTHREADS: u32 = 8;
+        const AMT: u32 = 10000;
+        const NTHREADS: u32 = 8;
         let (tx, rx) = channel::<i32>();
 
         let t = thread::spawn(move|| {
@@ -1663,8 +1663,8 @@ mod sync_tests {
 
     #[test]
     fn stress_shared() {
-        static AMT: u32 = 1000;
-        static NTHREADS: u32 = 8;
+        const AMT: u32 = 1000;
+        const NTHREADS: u32 = 8;
         let (tx, rx) = sync_channel::<i32>(0);
         let (dtx, drx) = sync_channel::<()>(0);
 
diff --git a/src/libstd/sync/mpsc/select.rs b/src/libstd/sync/mpsc/select.rs
index 8de5bbc6206..2c14c9fe3f1 100644
--- a/src/libstd/sync/mpsc/select.rs
+++ b/src/libstd/sync/mpsc/select.rs
@@ -473,7 +473,7 @@ mod test {
 
     #[test]
     fn stress() {
-        static AMT: i32 = 10000;
+        const AMT: i32 = 10000;
         let (tx1, rx1) = channel::<i32>();
         let (tx2, rx2) = channel::<i32>();
         let (tx3, rx3) = channel::<()>();
diff --git a/src/libstd/sync/mutex.rs b/src/libstd/sync/mutex.rs
index 4c3b5d98a3c..6f0febd61e8 100644
--- a/src/libstd/sync/mutex.rs
+++ b/src/libstd/sync/mutex.rs
@@ -390,8 +390,8 @@ mod test {
     fn lots_and_lots() {
         static M: StaticMutex = MUTEX_INIT;
         static mut CNT: u32 = 0;
-        static J: u32 = 1000;
-        static K: u32 = 3;
+        const J: u32 = 1000;
+        const K: u32 = 3;
 
         fn inc() {
             for _ in 0..J {
diff --git a/src/libstd/sync/rwlock.rs b/src/libstd/sync/rwlock.rs
index 454c5b4f0cf..e9ff6c0bf9d 100644
--- a/src/libstd/sync/rwlock.rs
+++ b/src/libstd/sync/rwlock.rs
@@ -436,8 +436,8 @@ mod tests {
     #[test]
     fn frob() {
         static R: StaticRwLock = RW_LOCK_INIT;
-        static N: usize = 10;
-        static M: usize = 1000;
+        const N: usize = 10;
+        const M: usize = 1000;
 
         let (tx, rx) = channel::<()>();
         for _ in 0..N {
diff --git a/src/libstd/sys/common/wtf8.rs b/src/libstd/sys/common/wtf8.rs
index fb9d6fef1fa..6cae127441c 100644
--- a/src/libstd/sys/common/wtf8.rs
+++ b/src/libstd/sys/common/wtf8.rs
@@ -43,7 +43,7 @@ use sys_common::AsInner;
 use unicode::str::{Utf16Item, utf16_items};
 use vec::Vec;
 
-static UTF8_REPLACEMENT_CHARACTER: &'static [u8] = b"\xEF\xBF\xBD";
+const UTF8_REPLACEMENT_CHARACTER: &'static [u8] = b"\xEF\xBF\xBD";
 
 /// A Unicode code point: from U+0000 to U+10FFFF.
 ///
diff --git a/src/libstd/sys/windows/os.rs b/src/libstd/sys/windows/os.rs
index 587ab7924fd..89cf8a08a68 100644
--- a/src/libstd/sys/windows/os.rs
+++ b/src/libstd/sys/windows/os.rs
@@ -59,8 +59,8 @@ pub fn error_string(errnum: i32) -> String {
                           -> DWORD;
     }
 
-    static FORMAT_MESSAGE_FROM_SYSTEM: DWORD = 0x00001000;
-    static FORMAT_MESSAGE_IGNORE_INSERTS: DWORD = 0x00000200;
+    const FORMAT_MESSAGE_FROM_SYSTEM: DWORD = 0x00001000;
+    const FORMAT_MESSAGE_IGNORE_INSERTS: DWORD = 0x00000200;
 
     // This value is calculated from the macro
     // MAKELANGID(LANG_SYSTEM_DEFAULT, SUBLANG_SYS_DEFAULT)
diff --git a/src/libstd/thread.rs b/src/libstd/thread.rs
index 5dd4be336ec..b0e79f2498d 100644
--- a/src/libstd/thread.rs
+++ b/src/libstd/thread.rs
@@ -853,7 +853,7 @@ mod test {
         // climbing the task tree to dereference each ancestor. (See #1789)
         // (well, it would if the constant were 8000+ - I lowered it to be more
         // valgrind-friendly. try this at home, instead..!)
-        static GENERATIONS: usize = 16;
+        const GENERATIONS: usize = 16;
         fn child_no(x: usize) -> Thunk<'static> {
             return Thunk::new(move|| {
                 if x < GENERATIONS {