blob: a75b16d042fd9eed710d6dfec3b0a5dc17454be3 [file] [log] [blame]
* Copyright 2017 The WebRTC Project Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
#include <algorithm>
#include <limits>
#include "webrtc/rtc_base/safe_minmax.h"
#include "webrtc/test/gtest.h"
namespace rtc {
namespace {
// Functions that check that SafeMin(), SafeMax(), and SafeClamp() return the
// specified type. The functions that end in "R" use an explicitly given return
// type.
template <typename T1, typename T2, typename Tmin, typename Tmax>
constexpr bool TypeCheckMinMax() {
return std::is_same<decltype(SafeMin(std::declval<T1>(), std::declval<T2>())),
Tmin>::value &&
std::is_same<decltype(SafeMax(std::declval<T1>(), std::declval<T2>())),
template <typename T1, typename T2, typename R>
constexpr bool TypeCheckMinR() {
return std::is_same<
decltype(SafeMin<R>(std::declval<T1>(), std::declval<T2>())), R>::value;
template <typename T1, typename T2, typename R>
constexpr bool TypeCheckMaxR() {
return std::is_same<
decltype(SafeMax<R>(std::declval<T1>(), std::declval<T2>())), R>::value;
template <typename T, typename L, typename H, typename R>
constexpr bool TypeCheckClamp() {
return std::is_same<decltype(SafeClamp(std::declval<T>(), std::declval<L>(),
template <typename T, typename L, typename H, typename R>
constexpr bool TypeCheckClampR() {
return std::is_same<decltype(SafeClamp<R>(std::declval<T>(),
// clang-format off
// SafeMin/SafeMax: Check that all combinations of signed/unsigned 8/64 bits
// give the correct default result type.
static_assert(TypeCheckMinMax< int8_t, int8_t, int8_t, int8_t>(), "");
static_assert(TypeCheckMinMax< int8_t, uint8_t, int8_t, uint8_t>(), "");
static_assert(TypeCheckMinMax< int8_t, int64_t, int64_t, int64_t>(), "");
static_assert(TypeCheckMinMax< int8_t, uint64_t, int8_t, uint64_t>(), "");
static_assert(TypeCheckMinMax< uint8_t, int8_t, int8_t, uint8_t>(), "");
static_assert(TypeCheckMinMax< uint8_t, uint8_t, uint8_t, uint8_t>(), "");
static_assert(TypeCheckMinMax< uint8_t, int64_t, int64_t, int64_t>(), "");
static_assert(TypeCheckMinMax< uint8_t, uint64_t, uint8_t, uint64_t>(), "");
static_assert(TypeCheckMinMax< int64_t, int8_t, int64_t, int64_t>(), "");
static_assert(TypeCheckMinMax< int64_t, uint8_t, int64_t, int64_t>(), "");
static_assert(TypeCheckMinMax< int64_t, int64_t, int64_t, int64_t>(), "");
static_assert(TypeCheckMinMax< int64_t, uint64_t, int64_t, uint64_t>(), "");
static_assert(TypeCheckMinMax<uint64_t, int8_t, int8_t, uint64_t>(), "");
static_assert(TypeCheckMinMax<uint64_t, uint8_t, uint8_t, uint64_t>(), "");
static_assert(TypeCheckMinMax<uint64_t, int64_t, int64_t, uint64_t>(), "");
static_assert(TypeCheckMinMax<uint64_t, uint64_t, uint64_t, uint64_t>(), "");
// SafeClamp: Check that all combinations of signed/unsigned 8/64 bits give the
// correct result type.
static_assert(TypeCheckClamp< int8_t, int8_t, int8_t, int8_t>(), "");
static_assert(TypeCheckClamp< int8_t, int8_t, uint8_t, int8_t>(), "");
static_assert(TypeCheckClamp< int8_t, int8_t, int64_t, int8_t>(), "");
static_assert(TypeCheckClamp< int8_t, int8_t, uint64_t, int8_t>(), "");
static_assert(TypeCheckClamp< int8_t, uint8_t, int8_t, int8_t>(), "");
static_assert(TypeCheckClamp< int8_t, uint8_t, uint8_t, uint8_t>(), "");
static_assert(TypeCheckClamp< int8_t, uint8_t, int64_t, int16_t>(), "");
static_assert(TypeCheckClamp< int8_t, uint8_t, uint64_t, int16_t>(), "");
static_assert(TypeCheckClamp< int8_t, int64_t, int8_t, int8_t>(), "");
static_assert(TypeCheckClamp< int8_t, int64_t, uint8_t, int16_t>(), "");
static_assert(TypeCheckClamp< int8_t, int64_t, int64_t, int64_t>(), "");
static_assert(TypeCheckClamp< int8_t, int64_t, uint64_t, int64_t>(), "");
static_assert(TypeCheckClamp< int8_t, uint64_t, int8_t, int8_t>(), "");
static_assert(TypeCheckClamp< int8_t, uint64_t, uint8_t, int16_t>(), "");
static_assert(TypeCheckClamp< int8_t, uint64_t, int64_t, int64_t>(), "");
static_assert(TypeCheckClamp< int8_t, uint64_t, uint64_t, uint64_t>(), "");
static_assert(TypeCheckClamp< uint8_t, int8_t, int8_t, int8_t>(), "");
static_assert(TypeCheckClamp< uint8_t, int8_t, uint8_t, uint8_t>(), "");
static_assert(TypeCheckClamp< uint8_t, int8_t, int64_t, int16_t>(), "");
static_assert(TypeCheckClamp< uint8_t, int8_t, uint64_t, uint8_t>(), "");
static_assert(TypeCheckClamp< uint8_t, uint8_t, int8_t, uint8_t>(), "");
static_assert(TypeCheckClamp< uint8_t, uint8_t, uint8_t, uint8_t>(), "");
static_assert(TypeCheckClamp< uint8_t, uint8_t, int64_t, uint8_t>(), "");
static_assert(TypeCheckClamp< uint8_t, uint8_t, uint64_t, uint8_t>(), "");
static_assert(TypeCheckClamp< uint8_t, int64_t, int8_t, int8_t>(), "");
static_assert(TypeCheckClamp< uint8_t, int64_t, uint8_t, uint8_t>(), "");
static_assert(TypeCheckClamp< uint8_t, int64_t, int64_t, int64_t>(), "");
static_assert(TypeCheckClamp< uint8_t, int64_t, uint64_t, uint64_t>(), "");
static_assert(TypeCheckClamp< uint8_t, uint64_t, int8_t, uint8_t>(), "");
static_assert(TypeCheckClamp< uint8_t, uint64_t, uint8_t, uint8_t>(), "");
static_assert(TypeCheckClamp< uint8_t, uint64_t, int64_t, uint64_t>(), "");
static_assert(TypeCheckClamp< uint8_t, uint64_t, uint64_t, uint64_t>(), "");
static_assert(TypeCheckClamp< int64_t, int8_t, int8_t, int8_t>(), "");
static_assert(TypeCheckClamp< int64_t, int8_t, uint8_t, int16_t>(), "");
static_assert(TypeCheckClamp< int64_t, int8_t, int64_t, int64_t>(), "");
static_assert(TypeCheckClamp< int64_t, int8_t, uint64_t, int64_t>(), "");
static_assert(TypeCheckClamp< int64_t, uint8_t, int8_t, int8_t>(), "");
static_assert(TypeCheckClamp< int64_t, uint8_t, uint8_t, int16_t>(), "");
static_assert(TypeCheckClamp< int64_t, uint8_t, int64_t, int64_t>(), "");
static_assert(TypeCheckClamp< int64_t, uint8_t, uint64_t, int64_t>(), "");
static_assert(TypeCheckClamp< int64_t, int64_t, int8_t, int64_t>(), "");
static_assert(TypeCheckClamp< int64_t, int64_t, uint8_t, int64_t>(), "");
static_assert(TypeCheckClamp< int64_t, int64_t, int64_t, int64_t>(), "");
static_assert(TypeCheckClamp< int64_t, int64_t, uint64_t, int64_t>(), "");
static_assert(TypeCheckClamp< int64_t, uint64_t, int8_t, int8_t>(), "");
static_assert(TypeCheckClamp< int64_t, uint64_t, uint8_t, int16_t>(), "");
static_assert(TypeCheckClamp< int64_t, uint64_t, int64_t, int64_t>(), "");
static_assert(TypeCheckClamp< int64_t, uint64_t, uint64_t, uint64_t>(), "");
static_assert(TypeCheckClamp<uint64_t, int8_t, int8_t, int8_t>(), "");
static_assert(TypeCheckClamp<uint64_t, int8_t, uint8_t, uint8_t>(), "");
static_assert(TypeCheckClamp<uint64_t, int8_t, int64_t, int64_t>(), "");
static_assert(TypeCheckClamp<uint64_t, int8_t, uint64_t, uint64_t>(), "");
static_assert(TypeCheckClamp<uint64_t, uint8_t, int8_t, uint8_t>(), "");
static_assert(TypeCheckClamp<uint64_t, uint8_t, uint8_t, uint8_t>(), "");
static_assert(TypeCheckClamp<uint64_t, uint8_t, int64_t, uint64_t>(), "");
static_assert(TypeCheckClamp<uint64_t, uint8_t, uint64_t, uint64_t>(), "");
static_assert(TypeCheckClamp<uint64_t, int64_t, int8_t, int8_t>(), "");
static_assert(TypeCheckClamp<uint64_t, int64_t, uint8_t, uint8_t>(), "");
static_assert(TypeCheckClamp<uint64_t, int64_t, int64_t, int64_t>(), "");
static_assert(TypeCheckClamp<uint64_t, int64_t, uint64_t, uint64_t>(), "");
static_assert(TypeCheckClamp<uint64_t, uint64_t, int8_t, uint8_t>(), "");
static_assert(TypeCheckClamp<uint64_t, uint64_t, uint8_t, uint8_t>(), "");
static_assert(TypeCheckClamp<uint64_t, uint64_t, int64_t, uint64_t>(), "");
static_assert(TypeCheckClamp<uint64_t, uint64_t, uint64_t, uint64_t>(), "");
enum DefaultE { kFoo = -17 };
enum UInt8E : uint8_t { kBar = 17 };
// SafeMin/SafeMax: Check that we can use enum types.
static_assert(TypeCheckMinMax<unsigned, unsigned, unsigned, unsigned>(), "");
static_assert(TypeCheckMinMax<unsigned, DefaultE, int, unsigned>(), "");
static_assert(TypeCheckMinMax<unsigned, UInt8E, uint8_t, unsigned>(), "");
static_assert(TypeCheckMinMax<DefaultE, unsigned, int, unsigned>(), "");
static_assert(TypeCheckMinMax<DefaultE, DefaultE, int, int>(), "");
static_assert(TypeCheckMinMax<DefaultE, UInt8E, int, int>(), "");
static_assert(TypeCheckMinMax< UInt8E, unsigned, uint8_t, unsigned>(), "");
static_assert(TypeCheckMinMax< UInt8E, DefaultE, int, int>(), "");
static_assert(TypeCheckMinMax< UInt8E, UInt8E, uint8_t, uint8_t>(), "");
// SafeClamp: Check that we can use enum types.
static_assert(TypeCheckClamp<unsigned, unsigned, unsigned, unsigned>(), "");
static_assert(TypeCheckClamp<unsigned, unsigned, DefaultE, unsigned>(), "");
static_assert(TypeCheckClamp<unsigned, unsigned, UInt8E, uint8_t>(), "");
static_assert(TypeCheckClamp<unsigned, DefaultE, unsigned, unsigned>(), "");
static_assert(TypeCheckClamp<unsigned, DefaultE, DefaultE, int>(), "");
static_assert(TypeCheckClamp<unsigned, DefaultE, UInt8E, uint8_t>(), "");
static_assert(TypeCheckClamp<unsigned, UInt8E, unsigned, unsigned>(), "");
static_assert(TypeCheckClamp<unsigned, UInt8E, DefaultE, unsigned>(), "");
static_assert(TypeCheckClamp<unsigned, UInt8E, UInt8E, uint8_t>(), "");
static_assert(TypeCheckClamp<DefaultE, unsigned, unsigned, unsigned>(), "");
static_assert(TypeCheckClamp<DefaultE, unsigned, DefaultE, int>(), "");
static_assert(TypeCheckClamp<DefaultE, unsigned, UInt8E, int16_t>(), "");
static_assert(TypeCheckClamp<DefaultE, DefaultE, unsigned, int>(), "");
static_assert(TypeCheckClamp<DefaultE, DefaultE, DefaultE, int>(), "");
static_assert(TypeCheckClamp<DefaultE, DefaultE, UInt8E, int>(), "");
static_assert(TypeCheckClamp<DefaultE, UInt8E, unsigned, int>(), "");
static_assert(TypeCheckClamp<DefaultE, UInt8E, DefaultE, int>(), "");
static_assert(TypeCheckClamp<DefaultE, UInt8E, UInt8E, int16_t>(), "");
static_assert(TypeCheckClamp< UInt8E, unsigned, unsigned, unsigned>(), "");
static_assert(TypeCheckClamp< UInt8E, unsigned, DefaultE, unsigned>(), "");
static_assert(TypeCheckClamp< UInt8E, unsigned, UInt8E, uint8_t>(), "");
static_assert(TypeCheckClamp< UInt8E, DefaultE, unsigned, unsigned>(), "");
static_assert(TypeCheckClamp< UInt8E, DefaultE, DefaultE, int>(), "");
static_assert(TypeCheckClamp< UInt8E, DefaultE, UInt8E, uint8_t>(), "");
static_assert(TypeCheckClamp< UInt8E, UInt8E, unsigned, uint8_t>(), "");
static_assert(TypeCheckClamp< UInt8E, UInt8E, DefaultE, uint8_t>(), "");
static_assert(TypeCheckClamp< UInt8E, UInt8E, UInt8E, uint8_t>(), "");
using ld = long double;
// SafeMin/SafeMax: Check that all floating-point combinations give the
// correct result type.
static_assert(TypeCheckMinMax< float, float, float, float>(), "");
static_assert(TypeCheckMinMax< float, double, double, double>(), "");
static_assert(TypeCheckMinMax< float, ld, ld, ld>(), "");
static_assert(TypeCheckMinMax<double, float, double, double>(), "");
static_assert(TypeCheckMinMax<double, double, double, double>(), "");
static_assert(TypeCheckMinMax<double, ld, ld, ld>(), "");
static_assert(TypeCheckMinMax< ld, float, ld, ld>(), "");
static_assert(TypeCheckMinMax< ld, double, ld, ld>(), "");
static_assert(TypeCheckMinMax< ld, ld, ld, ld>(), "");
// SafeClamp: Check that all floating-point combinations give the correct
// result type.
static_assert(TypeCheckClamp< float, float, float, float>(), "");
static_assert(TypeCheckClamp< float, float, double, double>(), "");
static_assert(TypeCheckClamp< float, float, ld, ld>(), "");
static_assert(TypeCheckClamp< float, double, float, double>(), "");
static_assert(TypeCheckClamp< float, double, double, double>(), "");
static_assert(TypeCheckClamp< float, double, ld, ld>(), "");
static_assert(TypeCheckClamp< float, ld, float, ld>(), "");
static_assert(TypeCheckClamp< float, ld, double, ld>(), "");
static_assert(TypeCheckClamp< float, ld, ld, ld>(), "");
static_assert(TypeCheckClamp<double, float, float, double>(), "");
static_assert(TypeCheckClamp<double, float, double, double>(), "");
static_assert(TypeCheckClamp<double, float, ld, ld>(), "");
static_assert(TypeCheckClamp<double, double, float, double>(), "");
static_assert(TypeCheckClamp<double, double, double, double>(), "");
static_assert(TypeCheckClamp<double, double, ld, ld>(), "");
static_assert(TypeCheckClamp<double, ld, float, ld>(), "");
static_assert(TypeCheckClamp<double, ld, double, ld>(), "");
static_assert(TypeCheckClamp<double, ld, ld, ld>(), "");
static_assert(TypeCheckClamp< ld, float, float, ld>(), "");
static_assert(TypeCheckClamp< ld, float, double, ld>(), "");
static_assert(TypeCheckClamp< ld, float, ld, ld>(), "");
static_assert(TypeCheckClamp< ld, double, float, ld>(), "");
static_assert(TypeCheckClamp< ld, double, double, ld>(), "");
static_assert(TypeCheckClamp< ld, double, ld, ld>(), "");
static_assert(TypeCheckClamp< ld, ld, float, ld>(), "");
static_assert(TypeCheckClamp< ld, ld, double, ld>(), "");
static_assert(TypeCheckClamp< ld, ld, ld, ld>(), "");
// clang-format on
// SafeMin/SafeMax: Check some cases of explicitly specified return type. The
// commented-out lines give compilation errors due to the requested return type
// being too small or requiring an int<->float conversion.
static_assert(TypeCheckMinR<int8_t, int8_t, int16_t>(), "");
// static_assert(TypeCheckMinR<int8_t, int8_t, float>(), "");
static_assert(TypeCheckMinR<uint32_t, uint64_t, uint32_t>(), "");
// static_assert(TypeCheckMaxR<uint64_t, float, float>(), "");
// static_assert(TypeCheckMaxR<uint64_t, double, float>(), "");
static_assert(TypeCheckMaxR<uint32_t, int32_t, uint32_t>(), "");
// static_assert(TypeCheckMaxR<uint32_t, int32_t, int32_t>(), "");
// SafeClamp: Check some cases of explicitly specified return type. The
// commented-out lines give compilation errors due to the requested return type
// being too small.
static_assert(TypeCheckClampR<int16_t, int8_t, uint8_t, int16_t>(), "");
static_assert(TypeCheckClampR<int16_t, int8_t, uint8_t, int32_t>(), "");
// static_assert(TypeCheckClampR<int16_t, int8_t, uint8_t, uint32_t>(), "");
template <typename T1, typename T2, typename Tmin, typename Tmax>
constexpr bool CheckMinMax(T1 a, T2 b, Tmin min, Tmax max) {
return TypeCheckMinMax<T1, T2, Tmin, Tmax>() && SafeMin(a, b) == min &&
SafeMax(a, b) == max;
template <typename T, typename L, typename H, typename R>
bool CheckClamp(T x, L min, H max, R clamped) {
return TypeCheckClamp<T, L, H, R>() && SafeClamp(x, min, max) == clamped;
// SafeMin/SafeMax: Check a few values.
static_assert(CheckMinMax(int8_t{1}, int8_t{-1}, int8_t{-1}, int8_t{1}), "");
static_assert(CheckMinMax(uint8_t{1}, int8_t{-1}, int8_t{-1}, uint8_t{1}), "");
static_assert(CheckMinMax(uint8_t{5}, uint64_t{2}, uint8_t{2}, uint64_t{5}),
// static_assert(CheckMinMax(1.f, 2, 1.f, 2.f), "");
static_assert(CheckMinMax(1.f, 0.0, 0.0, 1.0), "");
// SafeClamp: Check a few values.
TEST(SafeMinmaxTest, Clamp) {
EXPECT_TRUE(CheckClamp(int32_t{-1000000}, std::numeric_limits<int16_t>::min(),
EXPECT_TRUE(CheckClamp(uint32_t{1000000}, std::numeric_limits<int16_t>::min(),
EXPECT_TRUE(CheckClamp(3.f, -1.0, 1.f, 1.0));
EXPECT_TRUE(CheckClamp(3.0, -1.f, 1.f, 1.0));
} // namespace
// These functions aren't used in the tests, but it's useful to look at the
// compiler output for them, and verify that (1) the same-signedness Test*Safe
// functions result in exactly the same code as their Test*Ref counterparts,
// and that (2) the mixed-signedness Test*Safe functions have just a few extra
// arithmetic and logic instructions (but no extra control flow instructions).
// clang-format off
int32_t TestMinRef( int32_t a, int32_t b) { return std::min(a, b); }
uint32_t TestMinRef( uint32_t a, uint32_t b) { return std::min(a, b); }
int32_t TestMinSafe( int32_t a, int32_t b) { return SafeMin(a, b); }
int32_t TestMinSafe( int32_t a, uint32_t b) { return SafeMin(a, b); }
int32_t TestMinSafe(uint32_t a, int32_t b) { return SafeMin(a, b); }
uint32_t TestMinSafe(uint32_t a, uint32_t b) { return SafeMin(a, b); }
// clang-format on
int32_t TestClampRef(int32_t x, int32_t a, int32_t b) {
return std::max(a, std::min(x, b));
uint32_t TestClampRef(uint32_t x, uint32_t a, uint32_t b) {
return std::max(a, std::min(x, b));
int32_t TestClampSafe(int32_t x, int32_t a, int32_t b) {
return SafeClamp(x, a, b);
int32_t TestClampSafe(int32_t x, int32_t a, uint32_t b) {
return SafeClamp(x, a, b);
int32_t TestClampSafe(int32_t x, uint32_t a, int32_t b) {
return SafeClamp(x, a, b);
uint32_t TestClampSafe(int32_t x, uint32_t a, uint32_t b) {
return SafeClamp(x, a, b);
int32_t TestClampSafe(uint32_t x, int32_t a, int32_t b) {
return SafeClamp(x, a, b);
uint32_t TestClampSafe(uint32_t x, int32_t a, uint32_t b) {
return SafeClamp(x, a, b);
int32_t TestClampSafe(uint32_t x, uint32_t a, int32_t b) {
return SafeClamp(x, a, b);
uint32_t TestClampSafe(uint32_t x, uint32_t a, uint32_t b) {
return SafeClamp(x, a, b);
} // namespace rtc