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-rw-r--r--api/next/60427.txt4
-rw-r--r--doc/next/6-stdlib/99-minor/reflect/60427.md6
-rw-r--r--src/reflect/all_test.go41
-rw-r--r--src/reflect/type.go68
4 files changed, 118 insertions, 1 deletions
diff --git a/api/next/60427.txt b/api/next/60427.txt
new file mode 100644
index 0000000000..0be9da0782
--- /dev/null
+++ b/api/next/60427.txt
@@ -0,0 +1,4 @@
+pkg reflect, type Type interface, OverflowComplex(complex128) bool #60427
+pkg reflect, type Type interface, OverflowFloat(float64) bool #60427
+pkg reflect, type Type interface, OverflowInt(int64) bool #60427
+pkg reflect, type Type interface, OverflowUint(uint64) bool #60427
diff --git a/doc/next/6-stdlib/99-minor/reflect/60427.md b/doc/next/6-stdlib/99-minor/reflect/60427.md
new file mode 100644
index 0000000000..92230cde1a
--- /dev/null
+++ b/doc/next/6-stdlib/99-minor/reflect/60427.md
@@ -0,0 +1,6 @@
+The new methods synonymous with the method of the same name in [`reflect.Value`](/pkg/reflect#Value)
+are added to [`reflect.Type`](/pkg/reflect#Type):
+1. [`OverflowComplex`](/pkg/reflect#Type.OverflowComplex)
+2. [`OverflowFloat`](/pkg/reflect#Type.OverflowFloat)
+3. [`OverflowInt`](/pkg/reflect#Type.OverflowInt)
+4. [`OverflowUint`](/pkg/reflect#Type.OverflowUint)
diff --git a/src/reflect/all_test.go b/src/reflect/all_test.go
index c85de721a0..6e5c7d12e2 100644
--- a/src/reflect/all_test.go
+++ b/src/reflect/all_test.go
@@ -4827,7 +4827,7 @@ func TestComparable(t *testing.T) {
}
}
-func TestOverflow(t *testing.T) {
+func TestValueOverflow(t *testing.T) {
if ovf := V(float64(0)).OverflowFloat(1e300); ovf {
t.Errorf("%v wrongly overflows float64", 1e300)
}
@@ -4866,6 +4866,45 @@ func TestOverflow(t *testing.T) {
}
}
+func TestTypeOverflow(t *testing.T) {
+ if ovf := TypeFor[float64]().OverflowFloat(1e300); ovf {
+ t.Errorf("%v wrongly overflows float64", 1e300)
+ }
+
+ maxFloat32 := float64((1<<24 - 1) << (127 - 23))
+ if ovf := TypeFor[float32]().OverflowFloat(maxFloat32); ovf {
+ t.Errorf("%v wrongly overflows float32", maxFloat32)
+ }
+ ovfFloat32 := float64((1<<24-1)<<(127-23) + 1<<(127-52))
+ if ovf := TypeFor[float32]().OverflowFloat(ovfFloat32); !ovf {
+ t.Errorf("%v should overflow float32", ovfFloat32)
+ }
+ if ovf := TypeFor[float32]().OverflowFloat(-ovfFloat32); !ovf {
+ t.Errorf("%v should overflow float32", -ovfFloat32)
+ }
+
+ maxInt32 := int64(0x7fffffff)
+ if ovf := TypeFor[int32]().OverflowInt(maxInt32); ovf {
+ t.Errorf("%v wrongly overflows int32", maxInt32)
+ }
+ if ovf := TypeFor[int32]().OverflowInt(-1 << 31); ovf {
+ t.Errorf("%v wrongly overflows int32", -int64(1)<<31)
+ }
+ ovfInt32 := int64(1 << 31)
+ if ovf := TypeFor[int32]().OverflowInt(ovfInt32); !ovf {
+ t.Errorf("%v should overflow int32", ovfInt32)
+ }
+
+ maxUint32 := uint64(0xffffffff)
+ if ovf := TypeFor[uint32]().OverflowUint(maxUint32); ovf {
+ t.Errorf("%v wrongly overflows uint32", maxUint32)
+ }
+ ovfUint32 := uint64(1 << 32)
+ if ovf := TypeFor[uint32]().OverflowUint(ovfUint32); !ovf {
+ t.Errorf("%v should overflow uint32", ovfUint32)
+ }
+}
+
func checkSameType(t *testing.T, x Type, y any) {
if x != TypeOf(y) || TypeOf(Zero(x).Interface()) != TypeOf(y) {
t.Errorf("did not find preexisting type for %s (vs %s)", TypeOf(x), TypeOf(y))
diff --git a/src/reflect/type.go b/src/reflect/type.go
index 55d339fa39..89f33e6cf8 100644
--- a/src/reflect/type.go
+++ b/src/reflect/type.go
@@ -225,6 +225,22 @@ type Type interface {
// It panics if i is not in the range [0, NumOut()).
Out(i int) Type
+ // OverflowComplex reports whether the complex128 x cannot be represented by type t.
+ // It panics if t's Kind is not Complex64 or Complex128.
+ OverflowComplex(x complex128) bool
+
+ // OverflowFloat reports whether the float64 x cannot be represented by type t.
+ // It panics if t's Kind is not Float32 or Float64.
+ OverflowFloat(x float64) bool
+
+ // OverflowInt reports whether the int64 x cannot be represented by type t.
+ // It panics if t's Kind is not Int, Int8, Int16, Int32, or Int64.
+ OverflowInt(x int64) bool
+
+ // OverflowUint reports whether the uint64 x cannot be represented by type t.
+ // It panics if t's Kind is not Uint, Uintptr, Uint8, Uint16, Uint32, or Uint64.
+ OverflowUint(x uint64) bool
+
common() *abi.Type
uncommon() *uncommonType
}
@@ -297,6 +313,58 @@ type rtype struct {
t abi.Type
}
+// OverflowComplex reports whether the complex128 x cannot be represented by type t.
+// It panics if t's Kind is not Complex64 or Complex128.
+func (t *rtype) OverflowComplex(x complex128) bool {
+ k := t.Kind()
+ switch k {
+ case Complex64:
+ return overflowFloat32(real(x)) || overflowFloat32(imag(x))
+ case Complex128:
+ return false
+ }
+ panic("reflect: OverflowComplex of non-complex type " + t.String())
+}
+
+// OverflowFloat reports whether the float64 x cannot be represented by type t.
+// It panics if t's Kind is not Float32 or Float64.
+func (t *rtype) OverflowFloat(x float64) bool {
+ k := t.Kind()
+ switch k {
+ case Float32:
+ return overflowFloat32(x)
+ case Float64:
+ return false
+ }
+ panic("reflect: OverflowFloat of non-float type " + t.String())
+}
+
+// OverflowInt reports whether the int64 x cannot be represented by type t.
+// It panics if t's Kind is not Int, Int8, Int16, Int32, or Int64.
+func (t *rtype) OverflowInt(x int64) bool {
+ k := t.Kind()
+ switch k {
+ case Int, Int8, Int16, Int32, Int64:
+ bitSize := t.Size() * 8
+ trunc := (x << (64 - bitSize)) >> (64 - bitSize)
+ return x != trunc
+ }
+ panic("reflect: OverflowInt of non-int type " + t.String())
+}
+
+// OverflowUint reports whether the uint64 x cannot be represented by type t.
+// It panics if t's Kind is not Uint, Uintptr, Uint8, Uint16, Uint32, or Uint64.
+func (t *rtype) OverflowUint(x uint64) bool {
+ k := t.Kind()
+ switch k {
+ case Uint, Uintptr, Uint8, Uint16, Uint32, Uint64:
+ bitSize := t.Size() * 8
+ trunc := (x << (64 - bitSize)) >> (64 - bitSize)
+ return x != trunc
+ }
+ panic("reflect: OverflowUint of non-uint type " + t.String())
+}
+
func (t *rtype) common() *abi.Type {
return &t.t
}