Apply formatting/style tweaks to comply with compile time diagnostics for g++ and clang++ (#686)

* Add compilation flags: -Wshadow -Weffc++ -pedantic -pedantic-errors
* Delete implicit copy & move constructors & assignment operators
  in classes with pointer data members.
* An exception to the above: Add default copy & move constructors &
  assignment operators for the Binary class.
* Convert boolean RegEx operators to binary operators.
* Initialize all members in all classes in ctors.
* Let default ctor delegate to the converting ctor in
  Binary and RegEx
* Don't change any tests except regex_test (as a result of the change
  to binary operators).

Note: https://bugzilla.redhat.com/show_bug.cgi?id=1544675 makes
-Weffc++ report a false positive in "include/yaml-cpp/node/impl.h".

include/yaml-cpp/node/detail/memory.h

@@ -22,6 +22,7 @@ namespace YAML {
 namespace detail {
 class YAML_CPP_API memory {
  public:
+  memory() : m_nodes{} {}
   node& create_node();
   void merge(const memory& rhs);
 
@@ -40,7 +41,7 @@ class YAML_CPP_API memory_holder {
  private:
   shared_memory m_pMemory;
 };
-}
-}
+}  // namespace detail
+}  // namespace YAML
 
 #endif  // VALUE_DETAIL_MEMORY_H_62B23520_7C8E_11DE_8A39_0800200C9A66

include/yaml-cpp/node/detail/node.h

@@ -7,18 +7,18 @@
 #pragma once
 #endif
 
-#include "yaml-cpp/emitterstyle.h"
 #include "yaml-cpp/dll.h"
-#include "yaml-cpp/node/type.h"
-#include "yaml-cpp/node/ptr.h"
+#include "yaml-cpp/emitterstyle.h"
 #include "yaml-cpp/node/detail/node_ref.h"
+#include "yaml-cpp/node/ptr.h"
+#include "yaml-cpp/node/type.h"
 #include <set>
 
 namespace YAML {
 namespace detail {
 class node {
  public:
-  node() : m_pRef(new node_ref) {}
+  node() : m_pRef(new node_ref), m_dependencies{} {}
   node(const node&) = delete;
   node& operator=(const node&) = delete;
 
@@ -163,7 +163,7 @@ class node {
   typedef std::set<node*> nodes;
   nodes m_dependencies;
 };
-}
-}
+}  // namespace detail
+}  // namespace YAML
 
 #endif  // NODE_DETAIL_NODE_H_62B23520_7C8E_11DE_8A39_0800200C9A66

include/yaml-cpp/node/impl.h

@@ -7,15 +7,15 @@
 #pragma once
 #endif
 
-#include "yaml-cpp/node/node.h"
-#include "yaml-cpp/node/iterator.h"
+#include "yaml-cpp/exceptions.h"
 #include "yaml-cpp/node/detail/memory.h"
 #include "yaml-cpp/node/detail/node.h"
-#include "yaml-cpp/exceptions.h"
+#include "yaml-cpp/node/iterator.h"
+#include "yaml-cpp/node/node.h"
 #include <string>
 
 namespace YAML {
-inline Node::Node() : m_isValid(true), m_pNode(NULL) {}
+inline Node::Node() : m_isValid(true), m_pMemory(nullptr), m_pNode(nullptr) {}
 
 inline Node::Node(NodeType::value type)
     : m_isValid(true),
@@ -42,7 +42,7 @@ inline Node::Node(const Node& rhs)
       m_pMemory(rhs.m_pMemory),
       m_pNode(rhs.m_pNode) {}
 
-inline Node::Node(Zombie) : m_isValid(false), m_pNode(NULL) {}
+inline Node::Node(Zombie) : m_isValid(false), m_pMemory{}, m_pNode(nullptr) {}
 
 inline Node::Node(detail::node& node, detail::shared_memory_holder pMemory)
     : m_isValid(true), m_pMemory(pMemory), m_pNode(&node) {}
@@ -202,6 +202,15 @@ inline Node& Node::operator=(const T& rhs) {
   return *this;
 }
 
+inline Node& Node::operator=(const Node& rhs) {
+  if (!m_isValid || !rhs.m_isValid)
+    throw InvalidNode();
+  if (is(rhs))
+    return *this;
+  AssignNode(rhs);
+  return *this;
+}
+
 inline void Node::reset(const YAML::Node& rhs) {
   if (!m_isValid || !rhs.m_isValid)
     throw InvalidNode();
@@ -238,15 +247,6 @@ inline void Node::Assign(char* rhs) {
   m_pNode->set_scalar(rhs);
 }
 
-inline Node& Node::operator=(const Node& rhs) {
-  if (!m_isValid || !rhs.m_isValid)
-    throw InvalidNode();
-  if (is(rhs))
-    return *this;
-  AssignNode(rhs);
-  return *this;
-}
-
 inline void Node::AssignData(const Node& rhs) {
   if (!m_isValid || !rhs.m_isValid)
     throw InvalidNode();
@@ -366,7 +366,7 @@ template <typename T>
 inline typename to_value_t<T>::return_type to_value(const T& t) {
   return to_value_t<T>(t)();
 }
-}
+}  // namespace detail
 
 // indexing
 template <typename Key>
@@ -374,8 +374,8 @@ inline const Node Node::operator[](const Key& key) const {
   if (!m_isValid)
     throw InvalidNode();
   EnsureNodeExists();
-  detail::node* value = static_cast<const detail::node&>(*m_pNode)
-                            .get(detail::to_value(key), m_pMemory);
+  detail::node* value = static_cast<const detail::node&>(*m_pNode).get(
+      detail::to_value(key), m_pMemory);
   if (!value) {
     return Node(ZombieNode);
   }
@@ -443,6 +443,6 @@ inline void Node::force_insert(const Key& key, const Value& value) {
 
 // free functions
 inline bool operator==(const Node& lhs, const Node& rhs) { return lhs.is(rhs); }
-}
+}  // namespace YAML
 
 #endif  // NODE_IMPL_H_62B23520_7C8E_11DE_8A39_0800200C9A66