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POPolymorphic signature of function as template argument (using lambdas)
 

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    <p>I'm trying hard for some hours and didn't manage to get this working.</p> <p>I have a templated class spinlock:</p> <pre><code>template&lt;typename T&gt; class spinlock { // ... volatile T *shared_memory; }; </code></pre> <p>I'm trying to create something like this:</p> <pre><code> // inside spinlock class template&lt;typename F, typename... Ars&gt; std::result_of(F(Args...)) exec(F fun, Args&amp;&amp;... args) { // locks the memory and then executes fun(args...) }; </code></pre> <p>But I'm trying to use a polymorphic function so that I can do this:</p> <pre><code>spinlock&lt;int&gt; spin; int a = spin.exec([]() { return 10; }); int b = spin.exec([](int x) { return x; }, 10); // argument here, passed as x // If the signature matches the given arguments to exec() plus // the shared variable, call it int c = spin.exec([](volatile int &amp;shared) { return shared; }); // no extra arguments, shared becomes the // variable inside the spinlock class, I need to make // a function call that matches this as well // Same thing, matching the signature int d = spin.exec([](volatile int &amp;shared, int x) { return shared + x; }, 10); // extra argument, passed as x... should match too // Here, there would be an error int d = spin.exec([](volatile int &amp;shared, int x) { return shared + x; }); // since no extra argument was given </code></pre> <p>Basically, I'm trying to make an <code>exec</code> function that accepts <code>F(Args...)</code> or <code>F(volatile T &amp;, Args...)</code> as an argument.</p> <p>But I can't manage to make automatic detection of types. How could I accomplish that?</p>
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