update C++ version control & cmake script

Author: zhanghongce

CMakeLists.txt

@@ -20,6 +20,7 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
 
 
 install(TARGETS pstring
+    EXPORT pstringTargets
     ARCHIVE DESTINATION lib
     LIBRARY DESTINATION lib
     RUNTIME DESTINATION bin

include/pstring.h

@@ -6,8 +6,11 @@
 #include <iostream>
 #include <unordered_map>
 #if __cplusplus >= 202002L
+#include <version>
+#ifdef __cpp_lib_format
 #include <format>
 #endif
+#endif
 
 class PString {
 public:
@@ -43,10 +46,12 @@ class PString {
     int find(const PString& sub, size_t start=0, size_t end=std::string::npos) const;
 
 #if __cplusplus >= 202002L
+#ifdef __cpp_lib_format
     template <typename... Args>
     inline PString format(Args&&... args) const{
         return PString(std::vformat(std::string_view(this->str_), std::make_format_args(args...)));
     }
+#endif
 #endif
 
     int index(const PString& sub, size_t start=0, size_t end=std::string::npos) const;
@@ -201,6 +206,7 @@ namespace std {
 }
 
 #if __cplusplus >= 202002L
+#ifdef __cpp_lib_format
 template <>
 struct std::formatter<PString> {
     constexpr auto parse(std::format_parse_context& ctx) {
@@ -211,6 +217,7 @@ struct std::formatter<PString> {
     }
 };
 #endif
+#endif
 
 
 

test/test.cpp

@@ -2,7 +2,13 @@
 #include <vector>
 #include <string>
 #include <ostream>
+#include <version>
+#if __cplusplus >= 202002L
+#include <version>
+#ifdef __cpp_lib_format
 #include <format>
+#endif
+#endif
 #include <cassert>
 #include "pstring.h"
 
@@ -112,9 +118,11 @@ int main(){
     cout << str_count.repr() + ".count(\"abc\",1,9) = " << str_count.count("abc",1,9) << endl;
 
 #if __cplusplus >= 202002L
+#ifdef __cpp_lib_format
     PString fmt = "Hello, {}!";
     cout << fmt.repr() + ".format(\"World\") = " << fmt.format("World").repr() << endl;
 #endif
+#endif
 
 
     PString str_istitle1 = "Hello World!";
@@ -234,7 +242,9 @@ int main(){
     cout << str_equal_.repr() + " == " << str_equal_other3 << " = " << (str_equal_ == str_equal_other3) << std::endl;
 
 #if __cplusplus >= 202002L
+#ifdef __cpp_lib_format
     cout << std::format("str_equal: {}",str_equal) << std::endl;
+#endif
 #endif
     const_iter(PString("123abc"));