feat: Sync up with gno's math/overflow​ package

README.md

@@ -2,8 +2,9 @@
 # overflow
 Check for int/int8/int16/int64/int32 integer overflow in Golang arithmetic.
 ### Install
+
 ```
-go get github.com/johncgriffin/overflow
+go get github.com/gnolang/overflow
 ```
 Note that because Go has no template types, the majority of repetitive code is 
 generated by overflow_template.sh.  If you have to change an
@@ -13,7 +14,7 @@ go generate
 ```
 ### Synopsis
 
-```
+```go
 package main
 
 import "fmt"
@@ -22,18 +23,20 @@ import "github.com/JohnCGriffin/overflow"
 
 func main() {
 
-	addend := math.MaxInt64 - 5
+    addend := math.MaxInt64 - 5
 
-	for i := 0; i < 10; i++ {
-		sum, ok := overflow.Add(addend, i)
-		fmt.Printf("%v+%v -> (%v,%v)\n",
-			addend, i, sum, ok)
-	}
+    for i := 0; i < 10; i++ {
+        sum, ok := overflow.Add(addend, i)
+        fmt.Printf("%v+%v -> (%v,%v)\n",
+            addend, i, sum, ok)
+    }
 
 }
 ```
+
 yields the output
-```
+
+```plain
 9223372036854775802+0 -> (9223372036854775802,true)
 9223372036854775802+1 -> (9223372036854775803,true)
 9223372036854775802+2 -> (9223372036854775804,true)
@@ -54,10 +57,3 @@ Unsigned types not covered at the moment, but such additions are welcome.
 There's a good case to be made that a panic is an unidiomatic but proper response.  Iff you
 believe that there's no valid way to continue your program after math goes wayward, you can
 use the easier Addp, Mulp, Subp, and Divp versions which return the normal result or panic.
-
-
-
-
-
-
-

go.mod

@@ -0,0 +1,3 @@
+module github.com/gnolang/overflow
+
+go 1.23.1

overflow.go

@@ -1,4 +1,5 @@
-/*Package overflow offers overflow-checked integer arithmetic operations
+/*
+Package overflow offers overflow-checked integer arithmetic operations
 for int, int32, and int64. Each of the operations returns a
 result,bool combination.  This was prompted by the need to know when
 to flow into higher precision types from the math.big library.
@@ -16,17 +17,13 @@ overflow.Add(math.MaxInt64,1) -> (0, false)
 Add, Sub, Mul, Div are for int.  Add64, Add32, etc. are specifically sized.
 
 If anybody wishes an unsigned version, submit a pull request for code
-and new tests. */
+and new tests.
+*/
 package overflow
 
 //go:generate ./overflow_template.sh
 
-import "math"
-
-func _is64Bit() bool {
-	maxU32 := uint(math.MaxUint32)
-	return ((maxU32 << 1) >> 1) == maxU32
-}
+const is64Bit = ^uint(0) == (1<<64)-1
 
 /********** PARTIAL TEST COVERAGE FROM HERE DOWN *************
 
@@ -42,7 +39,7 @@ So, FEEL FREE to carefully review the code visually.
 
 // Add sums two ints, returning the result and a boolean status.
 func Add(a, b int) (int, bool) {
-	if _is64Bit() {
+	if is64Bit {
 		r64, ok := Add64(int64(a), int64(b))
 		return int(r64), ok
 	}
@@ -52,7 +49,7 @@ func Add(a, b int) (int, bool) {
 
 // Sub returns the difference of two ints and a boolean status.
 func Sub(a, b int) (int, bool) {
-	if _is64Bit() {
+	if is64Bit {
 		r64, ok := Sub64(int64(a), int64(b))
 		return int(r64), ok
 	}
@@ -62,7 +59,7 @@ func Sub(a, b int) (int, bool) {
 
 // Mul returns the product of two ints and a boolean status.
 func Mul(a, b int) (int, bool) {
-	if _is64Bit() {
+	if is64Bit {
 		r64, ok := Mul64(int64(a), int64(b))
 		return int(r64), ok
 	}
@@ -72,7 +69,7 @@ func Mul(a, b int) (int, bool) {
 
 // Div returns the quotient of two ints and a boolean status
 func Div(a, b int) (int, bool) {
-	if _is64Bit() {
+	if is64Bit {
 		r64, ok := Div64(int64(a), int64(b))
 		return int(r64), ok
 	}
@@ -82,14 +79,24 @@ func Div(a, b int) (int, bool) {
 
 // Quotient returns the quotient, remainder and status of two ints
 func Quotient(a, b int) (int, int, bool) {
-	if _is64Bit() {
+	if is64Bit {
 		q64, r64, ok := Quotient64(int64(a), int64(b))
 		return int(q64), int(r64), ok
 	}
 	q32, r32, ok := Quotient32(int32(a), int32(b))
 	return int(q32), int(r32), ok
 }
 
+// Quo returns the quotient, remainder and status of two ints
+func Quo(a, b int) (int, int, bool) {
+	if is64Bit {
+		q64, r64, ok := Quo64(int64(a), int64(b))
+		return int(q64), int(r64), ok
+	}
+	q32, r32, ok := Quo32(int32(a), int32(b))
+	return int(q32), int(r32), ok
+}
+
 /************* Panic versions for int ****************/
 
 // Addp returns the sum of two ints, panicking on overflow