Make XCTAssertEqual with accuracy more generic

Equality with accuracy isn't limited to floating point tests. Sometimes integer (or other numeric types) need to be accurate within
certain bounds for the purposes of testing. This change allows any numeric type that has magnitude and distance to be used with
`XCTAssertEqual(_:_:accuracy:)` and `XCTAssertNotEqual(_:_:accuracy:)`.

Author: gormster

Sources/XCTest/Public/XCTAssert.swift

@@ -171,12 +171,12 @@ public func XCTAssertEqual<T: Equatable>(_ expression1: @autoclosure () throws -
     }
 }
 
-public func XCTAssertEqual<T: FloatingPoint>(_ expression1: @autoclosure () throws -> T, _ expression2: @autoclosure () throws -> T, accuracy: T, _ message: @autoclosure () -> String = "", file: StaticString = #file, line: UInt = #line) {
+public func XCTAssertEqual<T: Strideable & Numeric>(_ expression1: @autoclosure () throws -> T, _ expression2: @autoclosure () throws -> T, accuracy: T, _ message: @autoclosure () -> String = "", file: StaticString = #file, line: UInt = #line) {
     _XCTEvaluateAssertion(.equalWithAccuracy, message: message(), file: file, line: line) {
         let (value1, value2) = (try expression1(), try expression2())
         // Test with equality first to handle comparing inf/-inf with itself.
         if value1 == value2 ||
-             abs(value1.distance(to: value2)) <= abs(accuracy.distance(to: T(0))) {
+             abs(value1.distance(to: value2)) <= abs(accuracy.distance(to: T.zero)) {
             return .success
         } else {
             return .expectedFailure("(\"\(value1)\") is not equal to (\"\(value2)\") +/- (\"\(accuracy)\")")
@@ -266,10 +266,10 @@ public func XCTAssertNotEqual<T: Equatable>(_ expression1: @autoclosure () throw
     }
 }
 
-public func XCTAssertNotEqual<T: FloatingPoint>(_ expression1: @autoclosure () throws -> T, _ expression2: @autoclosure () throws -> T, accuracy: T, _ message: @autoclosure () -> String = "", file: StaticString = #file, line: UInt = #line) {
+public func XCTAssertNotEqual<T: Strideable & Numeric>(_ expression1: @autoclosure () throws -> T, _ expression2: @autoclosure () throws -> T, accuracy: T, _ message: @autoclosure () -> String = "", file: StaticString = #file, line: UInt = #line) {
     _XCTEvaluateAssertion(.notEqualWithAccuracy, message: message(), file: file, line: line) {
         let (value1, value2) = (try expression1(), try expression2())
-        if abs(value1.distance(to: value2)) > abs(accuracy.distance(to: T(0))) {
+        if abs(value1.distance(to: value2)) > abs(accuracy.distance(to: T.zero)) {
             return .success
         } else {
             return .expectedFailure("(\"\(value1)\") is equal to (\"\(value2)\") +/- (\"\(accuracy)\")")