2bd028590d
Since we can't use the c++11 standard library, re-implement the bits we want to use now. TBR=reed@google.com The next CL is try to move SkTemplates into private. Review URL: https://codereview.chromium.org/1273813002
73 lines
1.9 KiB
C++
73 lines
1.9 KiB
C++
/*
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* Copyright 2015 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#ifndef SkFunction_DEFINED
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#define SkFunction_DEFINED
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// TODO: document, more pervasive move support in constructors, small-Fn optimization
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#include "SkTemplates.h"
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#include "SkTypes.h"
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template <typename> class SkFunction;
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template <typename R, typename... Args>
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class SkFunction<R(Args...)> {
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public:
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SkFunction() {}
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template <typename Fn>
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SkFunction(const Fn& fn) : fFunction(SkNEW_ARGS(LambdaImpl<Fn>, (fn))) {}
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SkFunction(R (*fn)(Args...)) : fFunction(SkNEW_ARGS(FnPtrImpl, (fn))) {}
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SkFunction(const SkFunction& other) { *this = other; }
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SkFunction& operator=(const SkFunction& other) {
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if (this != &other) {
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fFunction.reset(other.fFunction ? other.fFunction->clone() : nullptr);
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}
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return *this;
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}
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R operator()(Args... args) const {
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SkASSERT(fFunction.get());
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return fFunction->call(skstd::forward<Args>(args)...);
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}
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private:
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struct Interface {
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virtual ~Interface() {}
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virtual R call(Args...) const = 0;
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virtual Interface* clone() const = 0;
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};
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template <typename Fn>
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class LambdaImpl final : public Interface {
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public:
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LambdaImpl(const Fn& fn) : fFn(fn) {}
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R call(Args... args) const override { return fFn(skstd::forward<Args>(args)...); }
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Interface* clone() const override { return SkNEW_ARGS(LambdaImpl<Fn>, (fFn)); }
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private:
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Fn fFn;
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};
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class FnPtrImpl final : public Interface {
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public:
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FnPtrImpl(R (*fn)(Args...)) : fFn(fn) {}
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R call(Args... args) const override { return fFn(skstd::forward<Args>(args)...); }
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Interface* clone() const override { return SkNEW_ARGS(FnPtrImpl, (fFn)); }
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private:
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R (*fFn)(Args...);
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};
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SkAutoTDelete<Interface> fFunction;
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};
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#endif//SkFunction_DEFINED
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