common: add variadic template list utility functions

src/common/list_utils.h

@@ -0,0 +1,78 @@
+/*
+   mkvmerge -- utility for splicing together matroska files
+   from component media subtypes
+
+   Distributed under the GPL v2
+   see the file COPYING for details
+   or visit http://www.gnu.org/copyleft/gpl.html
+
+   list utility functions
+
+   Written by Moritz Bunkus <moritz@bunkus.org>.
+*/
+
+#ifndef MTX_COMMON_LIST_UTILS_H
+#define MTX_COMMON_LIST_UTILS_H
+
+namespace mtx {
+
+template<typename T>
+bool
+includes(T const &needle,
+         T const &val) {
+  return needle == val;
+}
+
+template<typename T,
+         typename... Trest>
+bool
+includes(T const &needle,
+         T const &val,
+         Trest... rest) {
+  return (needle == val) || includes(needle, rest...);
+}
+
+template<typename T>
+bool
+any_of(std::function<bool(T const &)> pred,
+       T const &val) {
+  return pred(val);
+}
+
+template<typename T,
+         typename... Trest>
+bool
+any_of(std::function<bool(T const &)> pred,
+       T const &val,
+       Trest... rest) {
+  return pred(val) || any_of(pred, rest...);
+}
+
+template<typename T>
+bool
+all_of(std::function<bool(T const &)> pred,
+       T const &val) {
+  return pred(val);
+}
+
+template<typename T,
+         typename... Trest>
+bool
+all_of(std::function<bool(T const &)> pred,
+       T const &val,
+       Trest... rest) {
+  return pred(val) && all_of(pred, rest...);
+}
+
+template<typename T,
+         typename... Trest>
+bool
+none_of(std::function<bool(T const &)> pred,
+        T const &val,
+        Trest... rest) {
+  return !any_of<T, Trest...>(pred, val, rest...);
+}
+
+}
+
+#endif  // MTX_COMMON_LIST_UTILS_H

tests/unit/common/list_utils.cpp

@@ -0,0 +1,57 @@
+#include "common/common_pch.h"
+
+#include "common/list_utils.h"
+
+#include "gtest/gtest.h"
+
+namespace {
+
+TEST(ListUtils, includes) {
+  EXPECT_TRUE(mtx::includes(42, 42));
+  EXPECT_TRUE(mtx::includes(42, 54, 42, 48));
+  EXPECT_TRUE(mtx::includes(42, 42, 54, 48));
+  EXPECT_TRUE(mtx::includes(42, 54, 48, 42));
+
+  EXPECT_FALSE(mtx::includes(23, 42));
+  EXPECT_FALSE(mtx::includes(23, 54, 42, 48));
+  EXPECT_FALSE(mtx::includes(23, 42, 54, 48));
+  EXPECT_FALSE(mtx::includes(23, 54, 48, 42));
+}
+
+TEST(ListUtils, any_of) {
+  EXPECT_TRUE(mtx::any_of<int>([](int val) { return val < 43; }, 42));
+  EXPECT_TRUE(mtx::any_of<int>([](int val) { return val < 43; }, 54, 42, 48));
+  EXPECT_TRUE(mtx::any_of<int>([](int val) { return val < 43; }, 42, 54, 48));
+  EXPECT_TRUE(mtx::any_of<int>([](int val) { return val < 43; }, 54, 48, 42));
+
+  EXPECT_FALSE(mtx::any_of<int>([](int val) { return val > 64; }, 42));
+  EXPECT_FALSE(mtx::any_of<int>([](int val) { return val > 64; }, 54, 42, 48));
+  EXPECT_FALSE(mtx::any_of<int>([](int val) { return val > 64; }, 42, 54, 48));
+  EXPECT_FALSE(mtx::any_of<int>([](int val) { return val > 64; }, 54, 48, 42));
+}
+
+TEST(ListUtils, all_of) {
+  EXPECT_TRUE(mtx::all_of<int>([](int val) { return val < 64; }, 42));
+  EXPECT_TRUE(mtx::all_of<int>([](int val) { return val < 64; }, 54, 42, 48));
+  EXPECT_TRUE(mtx::all_of<int>([](int val) { return val < 64; }, 42, 54, 48));
+  EXPECT_TRUE(mtx::all_of<int>([](int val) { return val < 64; }, 54, 48, 42));
+
+  EXPECT_FALSE(mtx::all_of<int>([](int val) { return val < 42; }, 42));
+  EXPECT_FALSE(mtx::all_of<int>([](int val) { return val < 42; }, 54, 42, 48));
+  EXPECT_FALSE(mtx::all_of<int>([](int val) { return val < 42; }, 42, 54, 48));
+  EXPECT_FALSE(mtx::all_of<int>([](int val) { return val < 42; }, 54, 48, 42));
+}
+
+TEST(ListUtils, none_of) {
+  EXPECT_TRUE(mtx::none_of<int>([](int val) { return val > 64; }, 42));
+  EXPECT_TRUE(mtx::none_of<int>([](int val) { return val > 64; }, 54, 42, 48));
+  EXPECT_TRUE(mtx::none_of<int>([](int val) { return val > 64; }, 42, 54, 48));
+  EXPECT_TRUE(mtx::none_of<int>([](int val) { return val > 64; }, 54, 48, 42));
+
+  EXPECT_FALSE(mtx::none_of<int>([](int val) { return val < 56; }, 42));
+  EXPECT_FALSE(mtx::none_of<int>([](int val) { return val < 56; }, 54, 42, 48));
+  EXPECT_FALSE(mtx::none_of<int>([](int val) { return val < 56; }, 42, 54, 48));
+  EXPECT_FALSE(mtx::none_of<int>([](int val) { return val < 56; }, 54, 48, 42));
+}
+
+}