diff options
Diffstat (limited to 'src/reflect/value.go')
| -rw-r--r-- | src/reflect/value.go | 68 |
1 files changed, 34 insertions, 34 deletions
diff --git a/src/reflect/value.go b/src/reflect/value.go index 68b97e9229..ffdf789648 100644 --- a/src/reflect/value.go +++ b/src/reflect/value.go @@ -1514,46 +1514,46 @@ func TypeAssert[T any](v Value) (T, bool) { } typ := abi.TypeFor[T]() - if typ != v.typ() { - // We can't just return false here: - // - // var zero T - // return zero, false - // - // since this function should work in the same manner as v.Interface().(T) does. - // Thus we have to handle two cases specially. - // Return the element inside the interface. - // - // T is a concrete type and v is an interface. For example: - // - // var v any = int(1) - // val := ValueOf(&v).Elem() - // TypeAssert[int](val) == val.Interface().(int) - // - // T is a interface and v is an interface, but the iface types are different. For example: - // - // var v any = &someError{} - // val := ValueOf(&v).Elem() - // TypeAssert[error](val) == val.Interface().(error) - if v.kind() == Interface { - v, ok := packIfaceValueIntoEmptyIface(v).(T) - return v, ok - } + // If v is an interface, return the element inside the interface. + // + // T is a concrete type and v is an interface. For example: + // + // var v any = int(1) + // val := ValueOf(&v).Elem() + // TypeAssert[int](val) == val.Interface().(int) + // + // T is a interface and v is a non-nil interface value. For example: + // + // var v any = &someError{} + // val := ValueOf(&v).Elem() + // TypeAssert[error](val) == val.Interface().(error) + // + // T is a interface and v is a nil interface value. For example: + // + // var v error = nil + // val := ValueOf(&v).Elem() + // TypeAssert[error](val) == val.Interface().(error) + if v.kind() == Interface { + v, ok := packIfaceValueIntoEmptyIface(v).(T) + return v, ok + } - // T is an interface, v is a concrete type. For example: - // - // TypeAssert[any](ValueOf(1)) == ValueOf(1).Interface().(any) - // TypeAssert[error](ValueOf(&someError{})) == ValueOf(&someError{}).Interface().(error) - if typ.Kind() == abi.Interface { - v, ok := packEface(v).(T) - return v, ok - } + // If T is an interface and v is a concrete type. For example: + // + // TypeAssert[any](ValueOf(1)) == ValueOf(1).Interface().(any) + // TypeAssert[error](ValueOf(&someError{})) == ValueOf(&someError{}).Interface().(error) + if typ.Kind() == abi.Interface { + v, ok := packEface(v).(T) + return v, ok + } + // Both v and T must be concrete types. + // The only way for an type-assertion to match is if the types are equal. + if typ != v.typ() { var zero T return zero, false } - if v.flag&flagIndir == 0 { return *(*T)(unsafe.Pointer(&v.ptr)), true } |