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POC++ object function to function pointer
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copied!<p>I'm using a C library inside my C++ app. The library has a function with the following signature:</p> <pre><code>void awe_webview_set_callback_js_callback(awe_webview* webview, void (*callback)(awe_webview* caller, const awe_string* object_name, const awe_string* callback_name, const awe_jsarray* arguments)); </code></pre> <p>I'm trying to set a function as a call back and I'd like to be able to use the following class member function</p> <pre><code>void BattleScreen::HandleWebViewCallbacks(awe_webview* WebView, const awe_string* object, const awe_string* callback, const awe_jsarray* arguments) { //handling code } </code></pre> <p>I can't bind it directly and based on here <a href="http://www.parashift.com/c++-faq-lite/pointers-to-members.html#faq-33.2" rel="nofollow">http://www.parashift.com/c++-faq-lite/pointers-to-members.html#faq-33.2</a> I have a possible solution where I'd create a static member to handle the callback (since based on that site, it should be fine) and add a static instance of this class for the static member to call on.</p> <p>i.e. add the following to BattleScreen:</p> <pre><code>static BattleScreen* callbacktarget; static BattleScreen::TopLevelHandleWebViewCallbacks(awe_webview* WebView, const awe_string* object, const awe_string* callback, const awe_jsarray* arguments) { callbacktarget->HandleWebviewCallbacks(WebView, object, callback, arguments); } </code></pre> <p>bind it in the constructor like so:</p> <pre><code>awe_webview_set_callback_js_callback(this->GetWebView(), static_cast<void (*)(awe_webview*, const awe_string*, const awe_string*, const awe_jsarray*)>(&BattleScreen::TopLevelHandleWebViewCallbacks)); </code></pre> <p>and assign the object to callbacktarget in the constructor.</p> <pre><code>BattleScreen::callbacktarget = this; </code></pre> <p>The problem is I have no way of knowing how many of these classes I will have at any one time (It'll be minimal but possibly greater then 1). I considered making the callbacktarget a vector of BattleScreen* that i can iterate through inside TopLevelHandleWebViewCallbacks and compare like so:</p> <pre><code>if (callbacktargets[index]->GetWebview() == WebView) { callbacktargets[index]->HandleWebviewCallbacks(WebView, object, callback, arguments); } </code></pre> <p>but the problem here is that I'm only comparing the awe_webview pointers which seems like a really bad idea. The library is closed source and the awe_webview's are C constructs so I can't see what makes them up and if there are any properties that would make a more suitable comparison. Is there a good solution to this? </p> <p>If I'm being unclear or you need additional information let me know.</p> <p>Thanks in advance</p>

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