explicit

问题 First attempt and everything works fine: class Base { public: Base() {std::cout << "default ctor!\n"; } }; ... Base b{}; Base b_one = {}; Another way of implementation(add explicit ): class Base { public: explicit Base() {std::cout << "default ctor!\n"; } }; ... Base b{}; Base b_one = {}; // error! Why? I have read on cppreference that in both cases default initialization would be used and no diffences. From list initialization: Otherwise, If the braced-init-list is empty and T is a class

问题 How do I use pimpl for a templated class, when I explicitly instantiate the templates? All I need is an example code. What I have tried is: // MyTemplatedClass.h template< class T > class MyTemplatedClass { private: class Impl; Impl* _pimpl; public: void PublicMethod(); } Here my implementation goes: // MyTemplatedClass.cpp template< class T > class MyTemplatedClass<T>::Impl { public: void PublicMethod(); } template <class T> void MyTemplatedClass<T>::Impl::PublicMethod() { ... } Forwarding

问题 I have an app that has about 300,000 members and I would like to add push notifications to it. Unfortunately I originally created the app with a wildcat bundle id com.MyCompany.* and when I uploaded it to Apple and when I edited it in my plist file I made it say com.MyCompany.MyAppName Now that I want to add push notifications I have to make a unique (or EXPLICIT) app ID so I attempted to make one called com.MyCompany.MyAppName ... I got this error message: The bundle identifier you have

问题 i'm wondering why linkers can not do their job simply by consulting the information in the actual .dll files that got the actual implementation code ? i mean why linkers still need .lib files to do implicit linking ? are not the export and relative address tables enough for such linking ? is there anyway by which one can do implicit linking using only the .dll without the .lib stub/proxy files ? i thought the windows executable loader would simply do LoadLibrary/LoadLibraryEx calls on behalf

问题 I am trying to create a global function template specialized for some given types. It looks something like that: A.h (primary template, template specialization, extern) template <typename T> void foo() { std::cout << "default stuff" << std::endl; } template<> void foo<int>() { std::cout << "int stuff" << std::endl; } extern template void foo<int>(); A.cpp (explicit instantiation) template void foo<int>(); B.h void bar(); B.cpp (includes A.h) void bar() { foo<int>(); } main.cpp foo<int>(); bar

问题 We have several hundred test classes, with a few dozen of them marked with the following attributes: [TestFixture] [Explicit] [Category("IntegrationTests")] so they will only be run in our over-night automated build. The remaining TestFixtures don't have a Category specified (and are not marked Explicit either). Here is the NAnt task we are running to execute our tests: <nunit2> <test> ... <categories> <include name="IntegrationTests" /> </categories> ... </test> </nunit2> This, of course,

问题 class Foo { public: explicit Foo() {} explicit Foo(Foo&) {} }; Foo d = Foo(); error: no matching function for call to 'Foo::Foo(Foo)' I tried changing Foo(Foo&) to Foo(Foo) as the error suggests, which AFAIK is not a valid constructor, and sure enough I get: error: invalid constructor; you probably meant ‘Foo (const Foo&)’ What gives? How do I resolve this? (This is on GCC by the way) 回答1: There are two questionable things that you have in your copy constructor. First, you've made the copy

问题 After having found answers to many of my questions on stackoverflow, I have now come up against a question of which I can't find the answer and I hope that someone is willing to help me! My problem is that I want to do an explicit templatization of a function inside a class in C++. My compiler (g++) and a look in the C++ standard (§14.7.3) tells me that this specialization has to be done in the namespace in which the class is declared. I understand that this implies that I cannot put the

问题 I know you can use C++ keyword 'explicit' for constructors of classes to prevent an automatic conversion of type. Can you use this same command to prevent the conversion of parameters for a class method? I have two class members, one which takes a bool as a param, the other an unsigned int. When I called the function with an int, the compiler converted the param to a bool and called the wrong method. I know eventually I'll replace the bool, but for now don't want to break the other routines

问题 So I've been attempting to find the solution to this but so far everything I've read online has to do with scope issues and not declaring the variables with the my keyword. However, I can't seem to fix the issues because I've declared everything at the top and, to me at least, it seems I don't have scope issues. My errors for the following code are: Global symbol "$filename" requires explicit package name at read_ids.pl line 6. Global symbol "$filename" requires explicit package name at read