Create TestRanges.cpp

cpp/c++23/TestRanges.cpp

@@ -0,0 +1,32 @@
+#include <iostream>
+#include <ranges>
+// 不太清楚这个头文件，cppreference查到contains是包含在algorithm
+#include <vector>
+#include <algorithm>
+
+int main() {
+    std::vector<int> numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+
+    // 使用新的 ranges 适配器
+    auto even_numbers = numbers | std::views::filter([](int n) { return n % 2 == 0; });
+    // lambda函数
+    auto squared_numbers = even_numbers | std::views::transform([](int n) { return n * n; });
+
+    for (int n : squared_numbers) {
+        std::cout << n << ' ';
+    }
+    std::cout << std::endl;
+
+    // 新的 range 算法
+    bool contains_five = std::ranges::contains(numbers, 5);
+    std::cout << "Contains 5: " << std::boolalpha << contains_five << std::endl;
+
+
+    // 获取前 5 个元素
+    auto first_five = numbers | std::views::take(5);
+
+    // 跳过前 5 个元素
+    auto after_five = numbers | std::views::drop(5);
+
+    return 0;
+}