Add read/write_json for i/ostream.

VirtualRobot/Util/json/io.cpp

@@ -4,6 +4,7 @@
 #include <filesystem>
 #include <fstream>
 
+
 namespace fs = std::filesystem;
 
 
@@ -28,9 +29,7 @@ namespace nlohmann
         try
         {
             ifs.open(filename);
-            json j;
-            ifs >> j;
-            return j;
+            return read_json(ifs);
         }
         catch (const std::ios_base::failure& e)
         {
@@ -42,6 +41,15 @@ namespace nlohmann
     }
 
 
+    json read_json(std::istream& is)
+    {
+        json j;
+        is >> j;
+        return j;
+    }
+
+
+
     void write_json(const std::string& filename, const json& j,
                     const int indent, const char indent_char)
     {
@@ -52,7 +60,7 @@ namespace nlohmann
         try
         {
             ofs.open(filename);
-            ofs << j.dump(indent, indent_char);
+            write_json(ofs, j, indent, indent_char);
         }
         catch (const std::ios_base::failure& e)
         {
@@ -62,6 +70,12 @@ namespace nlohmann
         }
     }
 
+
+    void write_json(std::ostream& os, const json& j, const int indent, const char indent_char)
+    {
+        os << j.dump(indent, indent_char);
+    }
+
 }
 
 

VirtualRobot/Util/json/io.h

@@ -8,27 +8,43 @@ namespace nlohmann
 
     /**
      * @brief Read a JSON document from the given file.
-     * 
+     *
      * @param filename The name of the file to read from.
      * @return The JSON document.
-     * 
+     *
      * @throw std::ios_base::failure If IO access fails.
      */
     json read_json(const std::string& filename);
-    
-    
+
     /**
-     * @brief Write a JSON document to the given file. 
-     * 
-     * @param j The JSON document.
+     * @brief Read a JSON document from the given in-stream.
+     * @param is The in-stream.
+     * @return The JSON document.
+     */
+    json read_json(std::istream& is);
+
+
+    /**
+     * @brief Write a JSON document to the given file.
+     *
      * @param filename The name of the file to write to.
+     * @param j The JSON document.
      * @param indent See nlohmann::json::dump().
      * @param indent_char See nlohmann::json::dump().
-     * 
+     *
      * @throw std::ios_base::failure If IO access fails.
      */
     void write_json(const std::string& filename, const json& j,
                     const int indent = -1, const char indent_char = ' ');
 
+    /**
+     * @brief Write a JSON document to the given out-stream.
+     * @param os The out-stream.
+     * @param j The JSON document.
+     * @param indent See nlohmann::json::dump().
+     * @param indent_char See nlohmann::json::dump().
+     */
+    void write_json(std::ostream& os, const json& j,
+                    const int indent = -1, const char indent_char = ' ');
 
 }