What is the correct way to initialize a very large struct? |
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memset is the way to go. You do not have many alternatives. Do something like: #define InitStruct(var, type) type var; memset(&var, 0, sizeof(type))So that you only have to: InitStruct(st, BigStruct);And then use st as usual... I do not get how "0" is not a valid "0" type for a struct. The only way to "mass initialize" a struct is to set all of its memory to a value; otherwise you would have to make extra logic to tell it to use a specific bit pattern per member. The best "generic" bit pattern to use is 0. Besides - this is the same logic that you used when doing *(controller->bigstruct) = *( struct bigstruct ){ 0 };Therefore I don't get your reluctance to use it :) The first comment to this post made me do some research before I called him and idiot and I found this: http://www.lysator.liu.se/c/c-faq/c-1.html Very interesting; if I could vote-up a comment I would :) That being said - your only option if you want to target archaic architectures with non-0 null values is still to do manual initialization to certain members. Thanks Thomas Padron-McCarthy! I learned something new today :) If you don't want to use memset, you could always declare a static copy of your struct and use memcpy, which will give similar performance. This will add 4 megs to your program but is probably better than setting individual elements. That said, if GCC was using memset, and it was good enough previously, I would suggest it is good enough now. |
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