Validator: Define virtual destructor in .cpp file

This fixes compiler warnings from clang:

src/training/validator.h:72:7: warning:
 'Validator' has no out-of-line virtual method definitions;
 its vtable will be emitted in every translation unit [-Wweak-vtables]

Signed-off-by: Stefan Weil <sw@weilnetz.de>

src/training/validator.cpp

@@ -24,6 +24,11 @@ const char32 Validator::kLeftToRightMark = 0x200E;
 const char32 Validator::kRightToLeftMark = 0x200F;
 const char32 Validator::kInvalid = 0xfffd;
 
+// Destructor.
+// It is defined here, so the compiler can create a single vtable
+// instead of weak vtables in every compilation unit.
+Validator::~Validator() = default;
+
 // Validates and cleans the src vector of unicodes to the *dest, according to
 // g_mode. In the case of kSingleString, a single vector containing the whole
 // result is added to *dest. With kCombined, multiple vectors are added to
@@ -175,7 +180,7 @@ ViramaScript Validator::MostFrequentViramaScript(
 bool Validator::IsVirama(char32 unicode) {
   return (kMinIndicUnicode <= unicode && unicode <= kMaxSinhalaUnicode &&
           (unicode & 0x7f) == 0x4d) ||
-         unicode == kSinhalaVirama || 
+         unicode == kSinhalaVirama ||
          unicode == kJavaneseVirama ||
          unicode == kMyanmarVirama ||
          unicode == kKhmerVirama;
@@ -193,8 +198,8 @@ bool Validator::IsVedicAccent(char32 unicode) {
 bool Validator::IsSubscriptScript() const {
   return script_ == ViramaScript::kTelugu ||
          script_ == ViramaScript::kKannada ||
-         script_ == ViramaScript::kJavanese || 
-         script_ == ViramaScript::kMyanmar || 
+         script_ == ViramaScript::kJavanese ||
+         script_ == ViramaScript::kMyanmar ||
          script_ == ViramaScript::kKhmer;
 }
 

src/training/validator.h

@@ -89,7 +89,7 @@ class Validator {
     return ch == kZeroWidthSpace || ch == kLeftToRightMark ||
            ch == kRightToLeftMark || ch == kInvalid;
   }
-  virtual ~Validator() {}
+  virtual ~Validator();
 
   // Some specific but universally useful unicodes.
   static const char32 kZeroWidthSpace;