1 files changed, 27 insertions, 0 deletions
diff --git a/lib/std/math/isnan.zig b/lib/std/math/isnan.zig
new file mode 100644
index 0000000000..cf8cd2e1c2
--- /dev/null
+++ b/lib/std/math/isnan.zig
@@ -0,0 +1,27 @@
+const std = @import("../std.zig");
+const math = std.math;
+const expect = std.testing.expect;
+const maxInt = std.math.maxInt;
+
+/// Returns whether x is a nan.
+pub fn isNan(x: var) bool {
+    return x != x;
+}
+
+/// Returns whether x is a signalling nan.
+pub fn isSignalNan(x: var) bool {
+    // Note: A signalling nan is identical to a standard nan right now but may have a different bit
+    // representation in the future when required.
+    return isNan(x);
+}
+
+test "math.isNan" {
+    expect(isNan(math.nan(f16)));
+    expect(isNan(math.nan(f32)));
+    expect(isNan(math.nan(f64)));
+    expect(isNan(math.nan(f128)));
+    expect(!isNan(f16(1.0)));
+    expect(!isNan(f32(1.0)));
+    expect(!isNan(f64(1.0)));
+    expect(!isNan(f128(1.0)));
+}