Use static function and member to improve performances

README.md

@@ -26,9 +26,10 @@ your CMakeLists.txt file looks like:
 
 ```cmake
 project("myapp")
-add_executable(${PROJECT_NAME} myapp.cpp)
 
-CPMAddPackage("gh:Teskann/blnscpp#master")  # Add this after add_executable / add_library, ...
+# Add BLNS cmake package
+CPMAddPackage("gh:Teskann/blnscpp#master")
+add_executable(${PROJECT_NAME} myapp.cpp)
 
 target_include_directories(${PROJECT_NAME} PRIVATE ${blnscpp_SOURCE_DIR}/include)  # Add include path
 target_link_libraries(${PROJECT_NAME} PRIVATE lib_blns)  # Link the blns library
@@ -41,8 +42,8 @@ With this setup, you can use blns like so in `myapp.cpp`:
 #include <iostream>
 
 int main() {
-    auto blns = blns::Blns();
-    for (auto const &ns : blns.getStrings()) {
+    for (auto const &ns : blns::Blns::getStrings())
+    {
         std::cout << ns << std::endl;
     }
 }

examples/example.cpp

@@ -2,8 +2,7 @@
 #include <iostream>
 
 int main() {
-    auto blns = blns::Blns{};
-    for (auto const &ns : blns.getStrings())
+    for (auto const &ns : blns::Blns::getStrings())
     {
         std::cout << ns << std::endl;
     }

include/blns/blns.h

@@ -15,18 +15,17 @@ namespace blns
 class Blns
 {
 public:
-    Blns();
-
-    ~Blns() = default;
 
     /*
      * Returns the list of Naughty Strings
      * @return list of naugthy strings
      */
-    [[nodiscard]] std::vector<std::string> const &getStrings() const;
+    [[nodiscard]] static std::vector<std::string> const &getStrings() ;
 
 private:
-    std::vector<std::string> blns;
+    inline static std::vector<std::string> blns;
+
+    static void readFile();
 };
 
 }

src/blns/blns.cpp

@@ -3,24 +3,27 @@
 #include <algorithm>
 #include <string>
 
-blns::Blns::Blns() {
-        std::ifstream blnsFile = std::filesystem::path(__FILE__).parent_path()
-                / ".." / ".." / "blns.txt";
+std::vector<std::string> const &blns::Blns::getStrings() {
+    if(blns.empty()) {
+        readFile();
+    }
+    return blns;
+}
 
-        // If this assertion fails, ensure that you have correctly
-        // downloaded blns.txt at the root of the project during cmake build
-        assert(blnsFile.is_open());
+void blns::Blns::readFile() {
+    std::ifstream blnsFile = std::filesystem::path(__FILE__).parent_path()
+                             / ".." / ".." / "blns.txt";
 
-        std::string line;
-        while(getline(blnsFile, line)) {
-            // Skip comments in txt file
-            if(line.rfind('#', 0) != 0) {
-                blns.push_back(line);
-            }
-        }
-        assert(!blns.empty());
-}
+    // If this assertion fails, ensure that you have correctly
+    // downloaded blns.txt at the root of the project during cmake build
+    assert(blnsFile.is_open());
 
-std::vector<std::string> const &blns::Blns::getStrings() const {
-    return blns;
+    std::string line;
+    while(getline(blnsFile, line)) {
+        // Skip comments in txt file
+        if(line.rfind('#', 0) != 0) {
+            blns.push_back(line);
+        }
+    }
+    assert(!blns.empty());
 }