Consider two libraries called Foo and Bar: using namespace foo; using namespace bar; Everything works fine, and you can call Blah() from Foo and Quux() from Bar without problems. But one day you upgrade to a new version of Foo 2.0, which now offers a function called Quux(). Now you’ve got a conflict: Both Foo … Read more
They are the same. To quote the C++11 standard (or the draft to be specific): A typedef-name can also be introduced by an alias-declaration. The identifier following the using keyword becomes a typedef-name and the optional attribute-specifier-seq following the identifier appertains to that typedef-name. It has the same semantics as if it were introduced by … Read more
Quoting an excerpt from C++ Primer (5th Edition) section “18.2.2. Using Namespace Members” The scope of names introduced by a using directive is more complicated than the scope of names in using declarations. As we’ve seen, a using declaration puts the name in the same scope as that of the using declaration itself. It is … Read more
The two options you state are not equivalent. This one: using namespace project1::namespace1; pulls in everything from the namespace, giving you little control and making clashes likely. I see only cons, and no pros here. But you don’t need to use a typedef to bring in a single symbol, you can use using project1::namespace1::class1; Whether … Read more
Someone else can find the standard quote but I’m going to explain conceptually. It doesn’t work because a using-declaration only affects name lookup. Your using-declaration causes name lookup to succeed where it would otherwise fail, that is, it tells the compiler where to find the function f. But it does not tell it which A … Read more
Why is “using System;” not considered bad practice? “using System;” is not universally not considered a bad practice. See for example: Why would you not use the ‘using’ directive in C#? But it may be true that it is not considered quite as bad as using namespace std. Probably because: C# does not have header … Read more
UPDATE – ReSharper 2016.1: This option is now moved to Code Editing → C# → Code Style → Add ‘using’ directive to the deepest scope Have you tried the ReSharper option: Languages → C# → Formatting Style → Namespace Imports → Add using directive to the deepest scope I’m not sure whether R#’s code cleanup … Read more
See this question. Turns out this was a client profiling issue. PrjForm was set to “.Net Framework 4 Client Profile” I changed it to “.Net Framework 4”, and now I have a successful build. Thanks everyone! I guess it figures that after all that time spent searching online, I find the solution minutes after posting, … Read more
Consider two libraries called Foo and Bar: using namespace foo; using namespace bar; Everything works fine, and you can call Blah() from Foo and Quux() from Bar without problems. But one day you upgrade to a new version of Foo 2.0, which now offers a function called Quux(). Now you’ve got a conflict: Both Foo … Read more