aliasing

std::vector<int> a; a.push_back(1); a.push_back(a[0]); I just learned that the code above can be very dangerous. (If it's not obvious why, you're not alone... it wasn't obvious to me either.) My questions: What is the "standard" way of dealing with it? Making a new variable and then assigning it immediately to something afterward seems a bit weird to me. Is there a better way of dealing with it? How do you train yourself to watch out for aliasing issues like this? What pattern(s) do you look for? I have no idea to recognize this situation; I only learned about aliasing when I learned about the

namespace A { #include <iostream> }; int main(){ A::std::cout << "\nSample"; return 0; } Short answer: No. Long answer: Well, not really. You can fake it, though. You can declare it outside and use using statements inside the namespace, like this: #include <iostream> namespace A { using std::cout; }; int main(){ A::cout << "\nSample"; system("PAUSE"); return 0; } You cannot localize a library, because even if it had access in A, it would not have access in the standard namespace. Also, "The other problem is that the qualified names inside the namespace would be A::std::cout, but the library

I understand that having a const method in C++ means that an object is read-only through that method, but that it may still change otherwise. However, this code apparently changes an object through a const reference (i.e. through a const method). Is this code legal in C++? If so: Is it breaking the const -ness of the type system? Why/why not? If not: Why not? Note 1: I have edited the example a bit, so answers might be referring to older examples. Edit 2: Apparently you don't even need C++11, so I removed that dependency. #include <iostream> using namespace std; struct DoBadThings { int *p;

I have created a stripped down JSFiddle of my D3 chart. I have made it responsive (with viewbox and preserveaspectratio) using the solution at: responsive D3 chart When I resize the window and make it smaller, some of the grid lines seem to be disappearing and reappearing. I presume this will look bad at small resolutions (eg. 320x480 mobile phone). Is there a way to preserve my gridlines when the window gets resized smaller? HTML code: <!--//d3 chart//--> <div class="centre-div"></div> CSS Code: .centre-div { margin: 0 auto; max-width: 550px; } /* D3 chart css */ .axis path, .axis line { fill

I'm using AlamofireImage to download and set my UIImage: backdrop.af_setImageWithURL(downloadURL) The image is substantially larger than what I will be displaying and so I have an issue with aliasing. How can I resize this image properly? Results: You can resize the image with any size once you have a valid UIImage : func resizedImageWith(image: UIImage, targetSize: CGSize) -> UIImage { let imageSize = image.size let newWidth = targetSize.width / image.size.width let newHeight = targetSize.height / image.size.height var newSize: CGSize if(newWidth > newHeight) { newSize = CGSizeMake(imageSize

Quote from C99 standard: 6.5.2.3 5 One special guarantee is made in order to simplify the use of unions: if a union contains several structures that share a common initial sequence (see below), and if the union object currently contains one of these structures, it is permitted to inspect the common initial part of any of them anywhere that a declaration of the complete type of the union is visible. Two structures share a common initial sequence if corresponding members have compatible types (and, for bit-fields, the same widths) for a sequence of one or more initial members. There is example