syntax: functions require return type. remove `->`

The purpose of this is:

 * Only one way to do things
 * Changing a function with void return type to return a possible
   error becomes a 1 character change, subtly encouraging
   people to use errors.

See #632

Here are some imperfect sed commands for performing this update:

remove arrow:

```
sed -i 's/\(\bfn\b.*\)-> /\1/g' $(find . -name "*.zig")
```

add void:

```
sed -i 's/\(\bfn\b.*\))\s*{/\1) void {/g' $(find ../ -name "*.zig")
```

Some cleanup may be necessary, but this should do the bulk of the work.

1 files changed, 3 insertions, 3 deletions

diff --git a/std/math/trunc.zig b/std/math/trunc.zig
index 1d9032a22c..54aa6943f7 100644
--- a/std/math/trunc.zig
+++ b/std/math/trunc.zig
@@ -8,7 +8,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn trunc(x: var) -> @typeOf(x) {
+pub fn trunc(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => trunc32(x),
@@ -17,7 +17,7 @@ pub fn trunc(x: var) -> @typeOf(x) {
     };
 }
 
-fn trunc32(x: f32) -> f32 {
+fn trunc32(x: f32) f32 {
     const u = @bitCast(u32, x);
     var e = i32(((u >> 23) & 0xFF)) - 0x7F + 9;
     var m: u32 = undefined;
@@ -38,7 +38,7 @@ fn trunc32(x: f32) -> f32 {
     }
 }
 
-fn trunc64(x: f64) -> f64 {
+fn trunc64(x: f64) f64 {
     const u = @bitCast(u64, x);
     var e = i32(((u >> 52) & 0x7FF)) - 0x3FF + 12;
     var m: u64 = undefined;