fix cpp lint in json11 (#2975)

* indent and constructor

* fix more

* fix long
Co-authored-by: StrikerRUS <nekit94-12@hotmail.com>

include/LightGBM/utils/json11.h

@@ -21,200 +21,206 @@
 
 /* json11
  *
- * json11 is a tiny JSON library for C++11, providing JSON parsing and serialization.
+ * json11 is a tiny JSON library for C++11, providing JSON parsing and
+ * serialization.
  *
- * The core object provided by the library is json11::Json. A Json object represents any JSON
- * value: null, bool, number (int or double), string (std::string), array (std::vector), or
- * object (std::map).
+ * The core object provided by the library is json11::Json. A Json object
+ * represents any JSON value: null, bool, number (int or double), string
+ * (std::string), array (std::vector), or object (std::map).
  *
- * Json objects act like values: they can be assigned, copied, moved, compared for equality or
- * order, etc. There are also helper methods Json::dump, to serialize a Json to a string, and
- * Json::parse (static) to parse a std::string as a Json object.
+ * Json objects act like values: they can be assigned, copied, moved, compared
+ * for equality or order, etc. There are also helper methods Json::dump, to
+ * serialize a Json to a string, and Json::parse (static) to parse a std::string
+ * as a Json object.
  *
- * Internally, the various types of Json object are represented by the JsonValue class
- * hierarchy.
+ * Internally, the various types of Json object are represented by the JsonValue
+ * class hierarchy.
  *
- * A note on numbers - JSON specifies the syntax of number formatting but not its semantics,
- * so some JSON implementations distinguish between integers and floating-point numbers, while
- * some don't. In json11, we choose the latter. Because some JSON implementations (namely
- * Javascript itself) treat all numbers as the same type, distinguishing the two leads
- * to JSON that will be *silently* changed by a round-trip through those implementations.
- * Dangerous! To avoid that risk, json11 stores all numbers as double internally, but also
+ * A note on numbers - JSON specifies the syntax of number formatting but not
+ * its semantics, so some JSON implementations distinguish between integers and
+ * floating-point numbers, while some don't. In json11, we choose the latter.
+ * Because some JSON implementations (namely Javascript itself) treat all
+ * numbers as the same type, distinguishing the two leads to JSON that will be
+ * *silently* changed by a round-trip through those implementations. Dangerous!
+ * To avoid that risk, json11 stores all numbers as double internally, but also
  * provides integer helpers.
  *
- * Fortunately, double-precision IEEE754 ('double') can precisely store any integer in the
- * range +/-2^53, which includes every 'int' on most systems. (Timestamps often use int64
- * or long long to avoid the Y2038K problem; a double storing microseconds since some epoch
- * will be exact for +/- 275 years.)
+ * Fortunately, double-precision IEEE754 ('double') can precisely store any
+ * integer in the range +/-2^53, which includes every 'int' on most systems.
+ * (Timestamps often use int64 or long long to avoid the Y2038K problem; a
+ * double storing microseconds since some epoch will be exact for +/- 275
+ * years.)
  */
 #pragma once
 
-#include <string>
 #include <initializer_list>
 #include <map>
 #include <memory>
+#include <string>
 #include <utility>
 #include <vector>
 
 namespace json11 {
 
-enum JsonParse {
-    STANDARD, COMMENTS
-};
+enum JsonParse { STANDARD, COMMENTS };
 
 class JsonValue;
 
 class Json final {
  public:
-    // Types
-    enum Type {
-        NUL, NUMBER, BOOL, STRING, ARRAY, OBJECT
-    };
-
-    // Array and object typedefs
-    typedef std::vector<Json> array;
-    typedef std::map<std::string, Json> object;
-
-    // Constructors for the various types of JSON value.
-    Json() noexcept;                 // NUL
-    Json(std::nullptr_t) noexcept;   // NUL
-    Json(double value);              // NUMBER
-    Json(int value);                 // NUMBER
-    Json(bool value);                // BOOL
-    Json(const std::string &value);  // STRING
-    Json(std::string &&value);       // STRING
-    Json(const char * value);        // STRING
-    Json(const array &values);       // ARRAY
-    Json(array &&values);            // ARRAY
-    Json(const object &values);      // OBJECT
-    Json(object &&values);           // OBJECT
-
-    // Implicit constructor: anything with a to_json() function.
-    template <class T, class = decltype(&T::to_json)>
-    Json(const T & t) : Json(t.to_json()) {}
-
-    // Implicit constructor: map-like objects (std::map, std::unordered_map, etc)
-    template <class M, typename std::enable_if<
-        std::is_constructible<std::string, decltype(std::declval<M>().begin()->first)>::value
-        && std::is_constructible<Json, decltype(std::declval<M>().begin()->second)>::value,
-            int>::type = 0>
-    Json(const M & m) : Json(object(m.begin(), m.end())) {}
-
-    // Implicit constructor: vector-like objects (std::list, std::vector, std::set, etc)
-    template <class V, typename std::enable_if<
-        std::is_constructible<Json, decltype(*std::declval<V>().begin())>::value,
-            int>::type = 0>
-    Json(const V & v) : Json(array(v.begin(), v.end())) {}
-
-    // This prevents Json(some_pointer) from accidentally producing a bool. Use
-    // Json(bool(some_pointer)) if that behavior is desired.
-    Json(void *) = delete;
-
-    // Accessors
-    Type type() const;
-
-    bool is_null()   const { return type() == NUL; }
-    bool is_number() const { return type() == NUMBER; }
-    bool is_bool()   const { return type() == BOOL; }
-    bool is_string() const { return type() == STRING; }
-    bool is_array()  const { return type() == ARRAY; }
-    bool is_object() const { return type() == OBJECT; }
-
-    // Return the enclosed value if this is a number, 0 otherwise. Note that json11 does not
-    // distinguish between integer and non-integer numbers - number_value() and int_value()
-    // can both be applied to a NUMBER-typed object.
-    double number_value() const;
-    int int_value() const;
-
-    // Return the enclosed value if this is a boolean, false otherwise.
-    bool bool_value() const;
-    // Return the enclosed string if this is a string, "" otherwise.
-    const std::string &string_value() const;
-    // Return the enclosed std::vector if this is an array, or an empty vector otherwise.
-    const array &array_items() const;
-    // Return the enclosed std::map if this is an object, or an empty map otherwise.
-    const object &object_items() const;
-
-    // Return a reference to arr[i] if this is an array, Json() otherwise.
-    const Json & operator[](size_t i) const;
-    // Return a reference to obj[key] if this is an object, Json() otherwise.
-    const Json & operator[](const std::string &key) const;
-
-    // Serialize.
-    void dump(std::string &out) const;
-    std::string dump() const {
-        std::string out;
-        dump(out);
-        return out;
+  // Types
+  enum Type { NUL, NUMBER, BOOL, STRING, ARRAY, OBJECT };
+
+  // Array and object typedefs
+  typedef std::vector<Json> array;
+  typedef std::map<std::string, Json> object;
+
+  // Constructors for the various types of JSON value.
+  Json() noexcept;                          // NUL
+  explicit Json(std::nullptr_t) noexcept;   // NUL
+  explicit Json(double value);              // NUMBER
+  explicit Json(int value);                 // NUMBER
+  explicit Json(bool value);                // BOOL
+  explicit Json(const std::string &value);  // STRING
+  explicit Json(std::string &&value);       // STRING
+  explicit Json(const char *value);         // STRING
+  explicit Json(const array &values);       // ARRAY
+  explicit Json(array &&values);            // ARRAY
+  explicit Json(const object &values);      // OBJECT
+  explicit Json(object &&values);           // OBJECT
+
+  // Implicit constructor: anything with a to_json() function.
+  template <class T, class = decltype(&T::to_json)>
+  explicit Json(const T &t) : Json(t.to_json()) {}
+
+  // Implicit constructor: map-like objects (std::map, std::unordered_map, etc)
+  template <
+      class M,
+      typename std::enable_if<
+          std::is_constructible<
+              std::string, decltype(std::declval<M>().begin()->first)>::value &&
+              std::is_constructible<
+                  Json, decltype(std::declval<M>().begin()->second)>::value,
+          int>::type = 0>
+  explicit Json(const M &m) : Json(object(m.begin(), m.end())) {}
+
+  // Implicit constructor: vector-like objects (std::list, std::vector,
+  // std::set, etc)
+  template <class V, typename std::enable_if<
+                         std::is_constructible<
+                             Json, decltype(*std::declval<V>().begin())>::value,
+                         int>::type = 0>
+  explicit Json(const V &v) : Json(array(v.begin(), v.end())) {}
+
+  // This prevents Json(some_pointer) from accidentally producing a bool. Use
+  // Json(bool(some_pointer)) if that behavior is desired.
+  explicit Json(void *) = delete;
+
+  // Accessors
+  Type type() const;
+
+  bool is_null() const { return type() == NUL; }
+  bool is_number() const { return type() == NUMBER; }
+  bool is_bool() const { return type() == BOOL; }
+  bool is_string() const { return type() == STRING; }
+  bool is_array() const { return type() == ARRAY; }
+  bool is_object() const { return type() == OBJECT; }
+
+  // Return the enclosed value if this is a number, 0 otherwise. Note that
+  // json11 does not distinguish between integer and non-integer numbers -
+  // number_value() and int_value() can both be applied to a NUMBER-typed
+  // object.
+  double number_value() const;
+  int int_value() const;
+
+  // Return the enclosed value if this is a boolean, false otherwise.
+  bool bool_value() const;
+  // Return the enclosed string if this is a string, "" otherwise.
+  const std::string &string_value() const;
+  // Return the enclosed std::vector if this is an array, or an empty vector
+  // otherwise.
+  const array &array_items() const;
+  // Return the enclosed std::map if this is an object, or an empty map
+  // otherwise.
+  const object &object_items() const;
+
+  // Return a reference to arr[i] if this is an array, Json() otherwise.
+  const Json &operator[](size_t i) const;
+  // Return a reference to obj[key] if this is an object, Json() otherwise.
+  const Json &operator[](const std::string &key) const;
+
+  // Serialize.
+  void dump(std::string *out) const;
+  std::string dump() const {
+    std::string out;
+    dump(&out);
+    return out;
+  }
+
+  // Parse. If parse fails, return Json() and assign an error message to err.
+  static Json parse(const std::string &in, std::string *err,
+                    JsonParse strategy = JsonParse::STANDARD);
+  static Json parse(const char *in, std::string *err,
+                    JsonParse strategy = JsonParse::STANDARD) {
+    if (in) {
+      return parse(std::string(in), err, strategy);
+    } else {
+      *err = "null input";
+      return Json(nullptr);
     }
-
-    // Parse. If parse fails, return Json() and assign an error message to err.
-    static Json parse(const std::string & in,
-                      std::string & err,
-                      JsonParse strategy = JsonParse::STANDARD);
-    static Json parse(const char * in,
-                      std::string & err,
-                      JsonParse strategy = JsonParse::STANDARD) {
-        if (in) {
-            return parse(std::string(in), err, strategy);
-        } else {
-            err = "null input";
-            return nullptr;
-        }
-    }
-    // Parse multiple objects, concatenated or separated by whitespace
-    static std::vector<Json> parse_multi(
-        const std::string & in,
-        std::string::size_type & parser_stop_pos,
-        std::string & err,
-        JsonParse strategy = JsonParse::STANDARD);
-
-    static inline std::vector<Json> parse_multi(
-        const std::string & in,
-        std::string & err,
-        JsonParse strategy = JsonParse::STANDARD) {
-        std::string::size_type parser_stop_pos;
-        return parse_multi(in, parser_stop_pos, err, strategy);
-    }
-
-    bool operator== (const Json &rhs) const;
-    bool operator<  (const Json &rhs) const;
-    bool operator!= (const Json &rhs) const { return !(*this == rhs); }
-    bool operator<= (const Json &rhs) const { return !(rhs < *this); }
-    bool operator>  (const Json &rhs) const { return  (rhs < *this); }
-    bool operator>= (const Json &rhs) const { return !(*this < rhs); }
-
-    /* has_shape(types, err)
-     *
-     * Return true if this is a JSON object and, for each item in types, has a field of
-     * the given type. If not, return false and set err to a descriptive message.
-     */
-    typedef std::initializer_list<std::pair<std::string, Type>> shape;
-    bool has_shape(const shape & types, std::string & err) const;
+  }
+  // Parse multiple objects, concatenated or separated by whitespace
+  static std::vector<Json> parse_multi(
+      const std::string &in, std::string::size_type *parser_stop_pos,
+      std::string *err, JsonParse strategy = JsonParse::STANDARD);
+
+  static inline std::vector<Json> parse_multi(
+      const std::string &in, std::string *err,
+      JsonParse strategy = JsonParse::STANDARD) {
+    std::string::size_type parser_stop_pos;
+    return parse_multi(in, &parser_stop_pos, err, strategy);
+  }
+
+  bool operator==(const Json &rhs) const;
+  bool operator<(const Json &rhs) const;
+  bool operator!=(const Json &rhs) const { return !(*this == rhs); }
+  bool operator<=(const Json &rhs) const { return !(rhs < *this); }
+  bool operator>(const Json &rhs) const { return (rhs < *this); }
+  bool operator>=(const Json &rhs) const { return !(*this < rhs); }
+
+  /* has_shape(types, err)
+   *
+   * Return true if this is a JSON object and, for each item in types, has a
+   * field of the given type. If not, return false and set err to a descriptive
+   * message.
+   */
+  typedef std::initializer_list<std::pair<std::string, Type>> shape;
+  bool has_shape(const shape &types, std::string *err) const;
 
  private:
-    std::shared_ptr<JsonValue> m_ptr;
+  std::shared_ptr<JsonValue> m_ptr;
 };
 
-// Internal class hierarchy - JsonValue objects are not exposed to users of this API.
+// Internal class hierarchy - JsonValue objects are not exposed to users of this
+// API.
 class JsonValue {
  protected:
-    friend class Json;
-    friend class JsonInt;
-    friend class JsonDouble;
-    virtual Json::Type type() const = 0;
-    virtual bool equals(const JsonValue * other) const = 0;
-    virtual bool less(const JsonValue * other) const = 0;
-    virtual void dump(std::string &out) const = 0;
-    virtual double number_value() const;
-    virtual int int_value() const;
-    virtual bool bool_value() const;
-    virtual const std::string &string_value() const;
-    virtual const Json::array &array_items() const;
-    virtual const Json &operator[](size_t i) const;
-    virtual const Json::object &object_items() const;
-    virtual const Json &operator[](const std::string &key) const;
-    virtual ~JsonValue() {}
+  friend class Json;
+  friend class JsonInt;
+  friend class JsonDouble;
+  virtual Json::Type type() const = 0;
+  virtual bool equals(const JsonValue *other) const = 0;
+  virtual bool less(const JsonValue *other) const = 0;
+  virtual void dump(std::string *out) const = 0;
+  virtual double number_value() const;
+  virtual int int_value() const;
+  virtual bool bool_value() const;
+  virtual const std::string &string_value() const;
+  virtual const Json::array &array_items() const;
+  virtual const Json &operator[](size_t i) const;
+  virtual const Json::object &object_items() const;
+  virtual const Json &operator[](const std::string &key) const;
+  virtual ~JsonValue() {}
 };
 
 }  // namespace json11

src/boosting/gbdt.cpp

@@ -64,7 +64,7 @@ void GBDT::Init(const Config* config, const Dataset* train_data, const Objective
     std::stringstream buffer;
     buffer << forced_splits_file.rdbuf();
     std::string err;
-    forced_splits_json_ = Json::parse(buffer.str(), err);
+    forced_splits_json_ = Json::parse(buffer.str(), &err);
   }
 
   objective_function_ = objective_function;
@@ -725,7 +725,7 @@ void GBDT::ResetConfig(const Config* config) {
       std::stringstream buffer;
       buffer << forced_splits_file.rdbuf();
       std::string err;
-      forced_splits_json_ = Json::parse(buffer.str(), err);
+      forced_splits_json_ = Json::parse(buffer.str(), &err);
       tree_learner_->SetForcedSplit(&forced_splits_json_);
     } else {
       forced_splits_json_ = Json();

src/io/dataset_loader.cpp

@@ -1208,7 +1208,7 @@ std::vector<std::vector<double>> DatasetLoader::GetForcedBins(std::string forced
       std::stringstream buffer;
       buffer << forced_bins_stream.rdbuf();
       std::string err;
-      Json forced_bins_json = Json::parse(buffer.str(), err);
+      Json forced_bins_json = Json::parse(buffer.str(), &err);
       CHECK(forced_bins_json.is_array());
       std::vector<Json> forced_bins_arr = forced_bins_json.array_items();
       for (size_t i = 0; i < forced_bins_arr.size(); ++i) {