Reland: Experimental parsing expression grammar (PEG) template library

include/core/SkTLazy.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkTLazy_DEFINED
 #define SkTLazy_DEFINED
 
 #include "../private/SkTemplates.h"
 #include "SkTypes.h"
 #include <new>
 #include <utility>
 
 /**
  *  Efficient way to defer allocating/initializing a class until it is needed
  *  (if ever).
  */
 template <typename T> class SkTLazy {
 public:
     SkTLazy() : fPtr(nullptr) {}
 
-    explicit SkTLazy(const T* src)
-        : fPtr(src ? new (fStorage.get()) T(*src) : nullptr) {}
+    explicit SkTLazy(const T* src) {
+        // Not in initializer list because it depends on fStorage.

[mtklein, 2016/08/24 01:19:28]

Alternatively, swap the order of the member variables?

[f(malita), 2016/08/24 13:47:29]

Done.

+        fPtr = src ? new (fStorage.get()) T(*src) : nullptr;
+    }
 
     SkTLazy(const SkTLazy& src) : fPtr(nullptr) { *this = src; }
 
     ~SkTLazy() {
         if (this->isValid()) {
             fPtr->~T();
         }
     }
 
     SkTLazy& operator=(const SkTLazy& src) {
@@ skipping 128 matching lines @@
     operator const T*() const { return fObj; }
 
     const T& operator *() const { return *fObj; }
 
 private:
     const T*    fObj;
     SkTLazy<T>  fLazy;
 };
 
 #endif