Pure async function for fs io without callbacks

lib/filesystem.hpp

@@ -12,7 +12,7 @@ using namespace std;
 namespace marcelb {
 
 /**
- * Asynchronous file reading
+ * Asynchronous file reading with callback after read complete
 */
 template<typename Callback>
 void asynco_read(string path, Callback&& callback) {
@@ -40,8 +40,32 @@ void asynco_read(string path, Callback&& callback) {
     });
 }
 
+
+/**
+ * Asynchronous file reading
+*/
+future<string> asynco_read(string path) {
+    return asynco( [&path] () {
+        string content;
+        string line;
+        ifstream file (path);
+        if (file.is_open()) {
+            line.clear();
+            while ( getline (file,line) ) {
+                content += line + "\n";
+            }
+            file.close();
+            return content;
+        }
+
+        else {
+            throw runtime_error("Unable to open file"); 
+        }
+    });
+}
+
 /**
- * Asynchronous file writing
+ * Asynchronous file writing with callback after write complete
 */
 template<typename Callback>
 void asynco_write(string path, string content, Callback&& callback) {
@@ -63,6 +87,25 @@ void asynco_write(string path, string content, Callback&& callback) {
     });
 }
 
+
+/**
+ * Asynchronous file writing with callback after write complete
+*/
+future<void> asynco_write(string path, string content) {
+    return asynco( [&path, &content] () {
+        ofstream file (path);
+        if (file.is_open()) {
+            file << content;
+            file.close();
+            return;
+        }
+        else {
+            throw runtime_error("Unable to open file"); 
+        }
+    });
+}
+
+
 }
 
 #endif

test/test.cpp

@@ -275,7 +275,7 @@ int main () {
     //     cout << "Constructed " << i  << endl;
     // });
 
-    // string data_;
+    string data_;
 
     // asynco_read("test.txt", [&data_] (string data, exception* error) {
     //     if (error) {
@@ -287,6 +287,15 @@ int main () {
     //     }
     // });
 
+    // auto data = asynco_read("test4.txt");
+
+    // try {
+    //     data_ = wait(data);
+    //     cout << "data" << data_ << endl;
+    // } catch (exception& err) {
+    //     cout << err.what() << endl;
+    // }
+
     // asynco_write("test1.txt", "Hello night", [] (exception* error) {
     //     if (error) {
     //         cout << "Error " << error->what() << endl;
@@ -295,6 +304,14 @@ int main () {
     //     }
     // });
 
+    auto status = asynco_write("test1.txt", "Hello night");
+
+
+    // try {
+    //     wait(status);
+    // } catch (exception& err) {
+    //     cout << err.what() << endl;
+    // }
 
     cout << "Sleep" << endl;
     sleep(100000); // only for testing