ITable: Const'ify getter functions.

include/networktables/NetworkTable.h

@@ -83,7 +83,7 @@ class NetworkTable : public ITable {
    *            the key name
    * @return the networktable to be returned
    */
-  std::shared_ptr<ITable> GetSubTable(llvm::StringRef key);
+  std::shared_ptr<ITable> GetSubTable(llvm::StringRef key) const;
 
   /**
    * Checks the table and tells if it contains the specified key
@@ -91,9 +91,9 @@ class NetworkTable : public ITable {
    * @param key
    *            the key to be checked
    */
-  bool ContainsKey(llvm::StringRef key);
+  bool ContainsKey(llvm::StringRef key) const;
 
-  bool ContainsSubTable(llvm::StringRef key);
+  bool ContainsSubTable(llvm::StringRef key) const;
 
   /**
    * Maps the specified key to the specified value in this table. The key can
@@ -117,7 +117,7 @@ class NetworkTable : public ITable {
    *            the default value if the key is null
    * @return the key
    */
-  double GetNumber(llvm::StringRef key, double defaultValue);
+  double GetNumber(llvm::StringRef key, double defaultValue) const;
 
   /**
    * Maps the specified key to the specified value in this table. The key can
@@ -141,7 +141,8 @@ class NetworkTable : public ITable {
    *            the default value if the key is null
    * @return the key
    */
-  std::string GetString(llvm::StringRef key, llvm::StringRef defaultValue);
+  std::string GetString(llvm::StringRef key,
+                        llvm::StringRef defaultValue) const;
 
   /**
    * Maps the specified key to the specified value in this table. The key can
@@ -165,7 +166,7 @@ class NetworkTable : public ITable {
    *            the default value if the key is null
    * @return the key
    */
-  bool GetBoolean(llvm::StringRef key, bool defaultValue);
+  bool GetBoolean(llvm::StringRef key, bool defaultValue) const;
 
   /**
    * Maps the specified key to the specified value in this table. The key can
@@ -186,7 +187,7 @@ class NetworkTable : public ITable {
    *            the key name
    * @return the key, or nullptr if the key is not defined
    */
-  std::shared_ptr<nt::Value> GetValue(llvm::StringRef key);
+  std::shared_ptr<nt::Value> GetValue(llvm::StringRef key) const;
 };
 
 #endif

include/tables/ITable.h

@@ -23,7 +23,7 @@ class ITable {
    * @param key the key to search for
    * @return true if the table as a value assigned to the given key
    */
-  virtual bool ContainsKey(llvm::StringRef key) = 0;
+  virtual bool ContainsKey(llvm::StringRef key) const = 0;
 
   /**
    * Determines whether there exists a non-empty subtable for this key
@@ -33,7 +33,7 @@ class ITable {
    * @return true if there is a subtable with the key which contains at least
    * one key/subtable of its own
    */
-  virtual bool ContainsSubTable(llvm::StringRef key) = 0;
+  virtual bool ContainsSubTable(llvm::StringRef key) const = 0;
 
   /**
    * Gets the subtable in this table for the given name.
@@ -41,7 +41,7 @@ class ITable {
    * @param key the name of the table relative to this one
    * @return a sub table relative to this one
    */
-  virtual std::shared_ptr<ITable> GetSubTable(llvm::StringRef key) = 0;
+  virtual std::shared_ptr<ITable> GetSubTable(llvm::StringRef key) const = 0;
 
   /**
    * Gets the value associated with a key as an object
@@ -51,7 +51,7 @@ class ITable {
    * @throws TableKeyNotDefinedException if there is no value associated with
    * the given key
    */
-  virtual std::shared_ptr<nt::Value> GetValue(llvm::StringRef key) = 0;
+  virtual std::shared_ptr<nt::Value> GetValue(llvm::StringRef key) const = 0;
 
   /**
    * Put a value in the table
@@ -80,7 +80,7 @@ class ITable {
    * @return the value associated with the given key or the given default value
    * if there is no value associated with the key
    */
-  virtual double GetNumber(llvm::StringRef key, double defaultValue) = 0;
+  virtual double GetNumber(llvm::StringRef key, double defaultValue) const = 0;
 
   /**
    * Put a string in the table
@@ -99,7 +99,7 @@ class ITable {
    * if there is no value associated with the key
    */
   virtual std::string GetString(llvm::StringRef key,
-                                llvm::StringRef defaultValue) = 0;
+                                llvm::StringRef defaultValue) const = 0;
 
   /**
    * Put a boolean in the table
@@ -117,7 +117,7 @@ class ITable {
    * @return the value associated with the given key or the given default value
    * if there is no value associated with the key
    */
-  virtual bool GetBoolean(llvm::StringRef key, bool defaultValue) = 0;
+  virtual bool GetBoolean(llvm::StringRef key, bool defaultValue) const = 0;
 
   /**
    * Add a listener for changes to the table

src/networktables/NetworkTable.cpp

@@ -99,21 +99,21 @@ void NetworkTable::RemoveTableListener(ITableListener* listener) {
   m_listeners.erase(matches_begin, m_listeners.end());
 }
 
-std::shared_ptr<ITable> NetworkTable::GetSubTable(StringRef key) {
+std::shared_ptr<ITable> NetworkTable::GetSubTable(StringRef key) const {
   llvm::SmallString<128> path(m_path);
   path += PATH_SEPARATOR_CHAR;
   path += key;
   return std::make_shared<NetworkTable>(path, private_init());
 }
 
-bool NetworkTable::ContainsKey(StringRef key) {
+bool NetworkTable::ContainsKey(StringRef key) const {
   llvm::SmallString<128> path(m_path);
   path += PATH_SEPARATOR_CHAR;
   path += key;
   return !nt::GetEntryValue(path);
 }
 
-bool NetworkTable::ContainsSubTable(StringRef key) {
+bool NetworkTable::ContainsSubTable(StringRef key) const {
   llvm::SmallString<128> path(m_path);
   path += PATH_SEPARATOR_CHAR;
   path += key;
@@ -128,7 +128,7 @@ void NetworkTable::PutNumber(StringRef key, double value) {
   nt::SetEntryValue(path, nt::Value::MakeDouble(value));
 }
 
-double NetworkTable::GetNumber(StringRef key, double defaultValue) {
+double NetworkTable::GetNumber(StringRef key, double defaultValue) const {
   llvm::SmallString<128> path(m_path);
   path += PATH_SEPARATOR_CHAR;
   path += key;
@@ -145,7 +145,8 @@ void NetworkTable::PutString(StringRef key, StringRef value) {
   nt::SetEntryValue(path, nt::Value::MakeString(value));
 }
 
-std::string NetworkTable::GetString(StringRef key, StringRef defaultValue) {
+std::string NetworkTable::GetString(StringRef key,
+                                    StringRef defaultValue) const {
   llvm::SmallString<128> path(m_path);
   path += PATH_SEPARATOR_CHAR;
   path += key;
@@ -162,7 +163,7 @@ void NetworkTable::PutBoolean(StringRef key, bool value) {
   nt::SetEntryValue(path, nt::Value::MakeBoolean(value));
 }
 
-bool NetworkTable::GetBoolean(StringRef key, bool defaultValue) {
+bool NetworkTable::GetBoolean(StringRef key, bool defaultValue) const {
   llvm::SmallString<128> path(m_path);
   path += PATH_SEPARATOR_CHAR;
   path += key;
@@ -179,7 +180,7 @@ void NetworkTable::PutValue(StringRef key, std::shared_ptr<nt::Value> value) {
   nt::SetEntryValue(path, value);
 }
 
-std::shared_ptr<nt::Value> NetworkTable::GetValue(StringRef key) {
+std::shared_ptr<nt::Value> NetworkTable::GetValue(StringRef key) const {
   llvm::SmallString<128> path(m_path);
   path += PATH_SEPARATOR_CHAR;
   path += key;