Make library buildable with -Werror=effc++

Adding initialization of several members to avoid the
error: ... should be initialized in the member initialization list

Deleting copy constructors and assignment operators for classes
with pointer data member to avoid the
error: ... has pointer data members but does not override ...

include/nlohmann/detail/input/binary_reader.hpp

@@ -52,6 +52,16 @@ class binary_reader
         assert(ia);
     }
 
+    ~binary_reader() = default;
+
+    // delete copy constructor and assignment operator since
+    // exclusive access to the input adapter is assumed
+    binary_reader(const binary_reader&) = delete;
+    binary_reader& operator=(const binary_reader&) = delete;
+
+    binary_reader(binary_reader&&) = default;
+    binary_reader& operator=(binary_reader&&) = default;
+
     /*!
     @param[in] format  the binary format to parse
     @param[in] sax_    a SAX event processor

include/nlohmann/detail/input/input_adapters.hpp

@@ -58,6 +58,14 @@ class file_input_adapter : public input_adapter_protocol
         : m_file(f)
     {}
 
+    // this class is only a wrapper around the file pointer and does
+    // not own it, so the defaults are safe
+    ~file_input_adapter() = default;
+    file_input_adapter(const file_input_adapter&) = default;
+    file_input_adapter& operator=(const file_input_adapter&) = default;
+    file_input_adapter(file_input_adapter&&) = default;
+    file_input_adapter& operator=(file_input_adapter&&) = default;
+
     std::char_traits<char>::int_type get_character() noexcept override
     {
         return std::fgetc(m_file);

include/nlohmann/detail/input/json_sax.hpp

@@ -158,6 +158,16 @@ class json_sax_dom_parser
         : root(r), allow_exceptions(allow_exceptions_)
     {}
 
+    ~json_sax_dom_parser() = default;
+
+    // delete copy constructor and assignment operator since
+    // exclusive access to the JSON value to be manipulated is assumed
+    json_sax_dom_parser(const json_sax_dom_parser&) = delete;
+    json_sax_dom_parser& operator=(const json_sax_dom_parser&) = delete;
+
+    json_sax_dom_parser(json_sax_dom_parser&&) = default;
+    json_sax_dom_parser& operator=(json_sax_dom_parser&&) = default;
+
     bool null()
     {
         handle_value(nullptr);
@@ -306,7 +316,7 @@ class json_sax_dom_parser
     /// the parsed JSON value
     BasicJsonType& root;
     /// stack to model hierarchy of values
-    std::vector<BasicJsonType*> ref_stack;
+    std::vector<BasicJsonType*> ref_stack {};
     /// helper to hold the reference for the next object element
     BasicJsonType* object_element = nullptr;
     /// whether a syntax error occurred
@@ -334,6 +344,16 @@ class json_sax_dom_callback_parser
         keep_stack.push_back(true);
     }
 
+    ~json_sax_dom_callback_parser() = default;
+
+    // delete copy constructor and assignment operator since
+    // exclusive access to the JSON value to be manipulated is assumed
+    json_sax_dom_callback_parser(const json_sax_dom_callback_parser&) = delete;
+    json_sax_dom_callback_parser& operator=(const json_sax_dom_callback_parser&) = delete;
+
+    json_sax_dom_callback_parser(json_sax_dom_callback_parser&&) = default;
+    json_sax_dom_callback_parser& operator=(json_sax_dom_callback_parser&&) = default;
+
     bool null()
     {
         handle_value(nullptr);
@@ -611,11 +631,11 @@ class json_sax_dom_callback_parser
     /// the parsed JSON value
     BasicJsonType& root;
     /// stack to model hierarchy of values
-    std::vector<BasicJsonType*> ref_stack;
+    std::vector<BasicJsonType*> ref_stack {};
     /// stack to manage which values to keep
-    std::vector<bool> keep_stack;
+    std::vector<bool> keep_stack {};
     /// stack to manage which object keys to keep
-    std::vector<bool> key_keep_stack;
+    std::vector<bool> key_keep_stack {};
     /// helper to hold the reference for the next object element
     BasicJsonType* object_element = nullptr;
     /// whether a syntax error occurred

include/nlohmann/detail/input/lexer.hpp

@@ -1483,7 +1483,7 @@ scan_number_done:
     bool next_unget = false;
 
     /// the start position of the current token
-    position_t position;
+    position_t position {};
 
     /// raw input token string (for error messages)
     std::vector<char> token_string {};

include/nlohmann/detail/iterators/iter_impl.hpp

@@ -607,7 +607,7 @@ class iter_impl
     /// associated JSON instance
     pointer m_object = nullptr;
     /// the actual iterator of the associated instance
-    internal_iterator<typename std::remove_const<BasicJsonType>::type> m_it;
+    internal_iterator<typename std::remove_const<BasicJsonType>::type> m_it {};
 };
 }  // namespace detail
-} // namespace nlohmann
+} // namespace nlohmann

single_include/nlohmann/json.hpp

@@ -2222,6 +2222,14 @@ class file_input_adapter : public input_adapter_protocol
         : m_file(f)
     {}
 
+    // this class is only a wrapper around the file pointer and does
+    // not own it, so the defaults are safe
+    ~file_input_adapter() = default;
+    file_input_adapter(const file_input_adapter&) = default;
+    file_input_adapter& operator=(const file_input_adapter&) = default;
+    file_input_adapter(file_input_adapter&&) = default;
+    file_input_adapter& operator=(file_input_adapter&&) = default;
+
     std::char_traits<char>::int_type get_character() noexcept override
     {
         return std::fgetc(m_file);
@@ -4074,7 +4082,7 @@ scan_number_done:
     bool next_unget = false;
 
     /// the start position of the current token
-    position_t position;
+    position_t position {};
 
     /// raw input token string (for error messages)
     std::vector<char> token_string {};
@@ -4420,6 +4428,16 @@ class json_sax_dom_parser
         : root(r), allow_exceptions(allow_exceptions_)
     {}
 
+    ~json_sax_dom_parser() = default;
+
+    // delete copy constructor and assignment operator since
+    // exclusive access to the JSON value to be manipulated is assumed
+    json_sax_dom_parser(const json_sax_dom_parser&) = delete;
+    json_sax_dom_parser& operator=(const json_sax_dom_parser&) = delete;
+
+    json_sax_dom_parser(json_sax_dom_parser&&) = default;
+    json_sax_dom_parser& operator=(json_sax_dom_parser&&) = default;
+
     bool null()
     {
         handle_value(nullptr);
@@ -4568,7 +4586,7 @@ class json_sax_dom_parser
     /// the parsed JSON value
     BasicJsonType& root;
     /// stack to model hierarchy of values
-    std::vector<BasicJsonType*> ref_stack;
+    std::vector<BasicJsonType*> ref_stack {};
     /// helper to hold the reference for the next object element
     BasicJsonType* object_element = nullptr;
     /// whether a syntax error occurred
@@ -4596,6 +4614,16 @@ class json_sax_dom_callback_parser
         keep_stack.push_back(true);
     }
 
+    ~json_sax_dom_callback_parser() = default;
+
+    // delete copy constructor and assignment operator since
+    // exclusive access to the JSON value to be manipulated is assumed
+    json_sax_dom_callback_parser(const json_sax_dom_callback_parser&) = delete;
+    json_sax_dom_callback_parser& operator=(const json_sax_dom_callback_parser&) = delete;
+
+    json_sax_dom_callback_parser(json_sax_dom_callback_parser&&) = default;
+    json_sax_dom_callback_parser& operator=(json_sax_dom_callback_parser&&) = default;
+
     bool null()
     {
         handle_value(nullptr);
@@ -4873,11 +4901,11 @@ class json_sax_dom_callback_parser
     /// the parsed JSON value
     BasicJsonType& root;
     /// stack to model hierarchy of values
-    std::vector<BasicJsonType*> ref_stack;
+    std::vector<BasicJsonType*> ref_stack {};
     /// stack to manage which values to keep
-    std::vector<bool> keep_stack;
+    std::vector<bool> keep_stack {};
     /// stack to manage which object keys to keep
-    std::vector<bool> key_keep_stack;
+    std::vector<bool> key_keep_stack {};
     /// helper to hold the reference for the next object element
     BasicJsonType* object_element = nullptr;
     /// whether a syntax error occurred
@@ -6223,10 +6251,11 @@ class iter_impl
     /// associated JSON instance
     pointer m_object = nullptr;
     /// the actual iterator of the associated instance
-    internal_iterator<typename std::remove_const<BasicJsonType>::type> m_it;
+    internal_iterator<typename std::remove_const<BasicJsonType>::type> m_it {};
 };
 }  // namespace detail
 } // namespace nlohmann
+
 // #include <nlohmann/detail/iterators/iteration_proxy.hpp>
 
 // #include <nlohmann/detail/iterators/json_reverse_iterator.hpp>
@@ -6532,6 +6561,16 @@ class binary_reader
         assert(ia);
     }
 
+    ~binary_reader() = default;
+
+    // delete copy constructor and assignment operator since
+    // exclusive access to the input adapter is assumed
+    binary_reader(const binary_reader&) = delete;
+    binary_reader& operator=(const binary_reader&) = delete;
+
+    binary_reader(binary_reader&&) = default;
+    binary_reader& operator=(binary_reader&&) = default;
+
     /*!
     @param[in] format  the binary format to parse
     @param[in] sax_    a SAX event processor

test/src/unit-alt-string.cpp

@@ -149,7 +149,7 @@ class alt_string
     }
 
   private:
-    std::string str_impl;
+    std::string str_impl {};
 
     friend bool ::operator<(const char*, const alt_string&);
 };

test/src/unit-class_parser.cpp

@@ -125,7 +125,7 @@ class SaxEventLogger
         return false;
     }
 
-    std::vector<std::string> events;
+    std::vector<std::string> events {};
     bool errored = false;
 };
 

test/src/unit-deserialization.cpp

@@ -123,7 +123,7 @@ struct SaxEventLogger : public nlohmann::json_sax<json>
         return false;
     }
 
-    std::vector<std::string> events;
+    std::vector<std::string> events {};
 };
 
 struct SaxEventLoggerExitAfterStartObject : public SaxEventLogger

test/src/unit-regression.cpp

@@ -124,8 +124,13 @@ struct nocopy
 
 struct Data
 {
-    std::string a;
-    std::string b;
+    Data() {}
+
+    Data(std::string a, std::string b)
+        : a(std::move(a)), b(std::move(b)) {}
+
+    std::string a {};
+    std::string b {};
 };
 
 void from_json(const json& j, Data& data)