Another effective [debugging] technique is to explain your code to someone else. This will often cause you to explain the bug to yourself. Sometimes it takes no more than a few sentences, followed by an embarrassed "Never mind. I see what's wrong. Sorry to bother you." This works remarkbly well; you can even use non-programmers as listeners.
- From "The Practice of Programming"
by Brian W Kernighan & Rob Pike.
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Unsafe Operations with STL !!!
It is UNSAFE to do any operation on an STL container that will modify its size while holding a reference to one of its exisiting element. What could happen is, when you do an operation, say push_back on a vector, it determines if there is enough space available to add a new element. If there is not sufficient space available, it allocates new space for whole of the data structure and deletes the old buffer. At this point, any reference to one of its elements created prior to push_back would have gotten corrupted.
For example, the following usage of code is dangerous when used within a single scope.
This is about a killer bug identified by our chief software engineer in our software. What was devised for ease of use and write smart code ended up in this killer defect due to improper perception. Ok, let us go!CComPtr is a template class in ATL designed to wrap the discrete functionality of COM object management - AddRef and Release. Technically it is a smart pointer for a COM object.void SomeMethod()
HRESULT hr = siPtr.CoCreateInstance(CLSID_SomeComponent);
}Without CComPtr, the code wouldn't be as elegant as above. The code would be spilled with AddRef and Release. Besides, writing code to Release after use under any circumstance is either hard or ugly. CComPtr automatically takes care of releasing in its destructor just like std::auto_ptr. As a C++ programmer, we must be able to appreciate the inevitability of the destructor and its immense use in writing smart code. However there is a difference between …
This post is primarily a personal reference. I also consider this a tribute to Oleg, who was fundamental in improving my understanding of the jqGrid internals - the way it handles source data types, which if I may say led him in discovering a bug in jqGrid.
If you are working with local array data as the source for jqGrid, meaning you will get the data from the server but want the jqGrid not to talk to the server anymore, and want to have custom handling of the edit functionality/form and delete functionality, it is not going to be straightforward - you need to have a decent understanding of how jqGrid works, and you should be aware of the bug Oleg pointed in our discussion. I repeat this is all about using jqGrid to manage array data locally, no posting to server when you edit or delete, which is where the bug is.
THIS POST USES SYNTAXHIGHLIGHTER AND HAS ISSUES RENDERING CODE ONLY IN CHROME Not the same way but we could say better. Visual Studio 2012, another power packed release of Visual Studio, among a lot of other powerful fancy language features, offers the ability to deduce the method caller details at compile time. C++ offered the compiler defined macros __FILE__ and __LINE__ (and __DATE__ and __TIME__), which are primarily intended for diagnostic purposes in a program, whereby the caller information is captured and logged. For instance, using __LINE__ would be replaced with the exact line number in the file where this macro has been used. That sometimes beats the purpose and doesn't gives us what we actually expect. Let's see.
For instance, suppose you wish to write a verbose Log method with an idea to print rich diagnostic details, it would look something like this. void LogException(const std::string& logText,
const std::string& fileName,