Added cpp_regex_error.cpp

cpp_regex_error.cpp

@@ -0,0 +1,18 @@
+// @COMPILECMD g++ $@ -o regex_error -std=c++20
+#include <iostream>
+#include <regex>
+
+int main() {
+    std::string input = "Hello world, this is a sample text with hello world.";
+
+    std::regex pattern("+hello\\s+world", std::regex_constants::icase); // Case-insensitive regex pattern
+
+    std::smatch matches;
+    if (std::regex_search(input, matches, pattern)) {
+        std::cout << "Found 'hello world' at position " << matches.position() << std::endl;
+    } else {
+        std::cout << "Pattern not found." << std::endl;
+    }
+
+    return 0;
+}