Add `From<{integer}>` for `f16`/`f128` impls

2 files changed, 43 insertions, 0 deletions

diff --git a/library/std/tests/floats/f128.rs b/library/std/tests/floats/f128.rs
index d0e8b157e6b..b4a6c672bf0 100644
--- a/library/std/tests/floats/f128.rs
+++ b/library/std/tests/floats/f128.rs
@@ -983,3 +983,34 @@ fn test_total_cmp() {
     assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&f128::INFINITY));
     assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&s_nan()));
 }
+
+#[test]
+fn test_from() {
+    assert_eq!(f128::from(false), 0.0);
+    assert_eq!(f128::from(true), 1.0);
+    assert_eq!(f128::from(u8::MIN), 0.0);
+    assert_eq!(f128::from(42_u8), 42.0);
+    assert_eq!(f128::from(u8::MAX), 255.0);
+    assert_eq!(f128::from(i8::MIN), -128.0);
+    assert_eq!(f128::from(42_i8), 42.0);
+    assert_eq!(f128::from(i8::MAX), 127.0);
+    assert_eq!(f128::from(u16::MIN), 0.0);
+    assert_eq!(f128::from(42_u16), 42.0);
+    assert_eq!(f128::from(u16::MAX), 65535.0);
+    assert_eq!(f128::from(i16::MIN), -32768.0);
+    assert_eq!(f128::from(42_i16), 42.0);
+    assert_eq!(f128::from(i16::MAX), 32767.0);
+    assert_eq!(f128::from(u32::MIN), 0.0);
+    assert_eq!(f128::from(42_u32), 42.0);
+    assert_eq!(f128::from(u32::MAX), 4294967295.0);
+    assert_eq!(f128::from(i32::MIN), -2147483648.0);
+    assert_eq!(f128::from(42_i32), 42.0);
+    assert_eq!(f128::from(i32::MAX), 2147483647.0);
+    // FIXME(f16_f128): Uncomment these tests once the From<{u64,i64}> impls are added.
+    // assert_eq!(f128::from(u64::MIN), 0.0);
+    // assert_eq!(f128::from(42_u64), 42.0);
+    // assert_eq!(f128::from(u64::MAX), 18446744073709551615.0);
+    // assert_eq!(f128::from(i64::MIN), -9223372036854775808.0);
+    // assert_eq!(f128::from(42_i64), 42.0);
+    // assert_eq!(f128::from(i64::MAX), 9223372036854775807.0);
+}
diff --git a/library/std/tests/floats/f16.rs b/library/std/tests/floats/f16.rs
index 5180f3d40f3..727f29e375b 100644
--- a/library/std/tests/floats/f16.rs
+++ b/library/std/tests/floats/f16.rs
@@ -955,3 +955,15 @@ fn test_total_cmp() {
     assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&f16::INFINITY));
     assert_eq!(Ordering::Less, (-s_nan()).total_cmp(&s_nan()));
 }
+
+#[test]
+fn test_from() {
+    assert_eq!(f16::from(false), 0.0);
+    assert_eq!(f16::from(true), 1.0);
+    assert_eq!(f16::from(u8::MIN), 0.0);
+    assert_eq!(f16::from(42_u8), 42.0);
+    assert_eq!(f16::from(u8::MAX), 255.0);
+    assert_eq!(f16::from(i8::MIN), -128.0);
+    assert_eq!(f16::from(42_i8), 42.0);
+    assert_eq!(f16::from(i8::MAX), 127.0);
+}