Add math library

This covers the majority of the functions as covered by the C99
specification for a math library.

Code is adapted primarily from musl libc, with the pow and standard
trigonometric functions adapted from the Go stdlib.

Changes:

 - Remove assert expose in index and import as needed.
 - Add float log function and merge with existing base 2 integer
   implementation.

See https://github.com/tiehuis/zig-fmath.
See #374.

1 files changed, 9 insertions, 0 deletions

diff --git a/std/math/nan.zig b/std/math/nan.zig
new file mode 100644
index 0000000000..bd079026a5
--- /dev/null
+++ b/std/math/nan.zig
@@ -0,0 +1,9 @@
+const math = @import("index.zig");
+
+pub fn nan(comptime T: type) -> T {
+    switch (T) {
+        f32 => @bitCast(f32, math.nan_u32),
+        f64 => @bitCast(f64, math.nan_u64),
+        else => @compileError("nan not implemented for " ++ @typeName(T)),
+    }
+}