generic-lambda

Consider the following code: int main() { auto l = [](auto){}; void(*p)(int) = l; } It works just fine both with GCC and clang . Let's consider the following slightly modified version: int main() { auto l = [](auto...){}; void(*p)(int) = l; } In this case, clang still accepts it while GCC rejects it . Is there any reason for which this code should be rejected or is it a bug of the compiler? I'm going to open an issue, but I'd like to know if there exists any proposal that could have been implemented by one of them and not by the other one. This is a known GCC parsing bug ( 64095 , 68071 ): []

Can generic lambdas take advantage of the "Substitution Failure Is Not An Error" rule ? Example auto gL = [](auto&& func, auto&& param1, auto&&... params) -> enable_if_t< is_integral< std::decay_t<decltype(param1)> >::value> { // ... }; auto gL = [](auto&& func, auto&& param1, auto&&... params) -> enable_if_t< !is_integral< std::decay_t<decltype(param1)> >::value> { // ... }; Are there any workarounds or plans to include this in the language ? Also since generic lambdas are templated function objects under the hood isn't it a bit odd that this can't be done ? Lambdas are function objects under

I can write a function template: template<typename T> void f1(T parameter) { ... } But in C++14, I can also create a generic lambda: auto f2 = [](auto parameter) { ... }; Within f1 I can refer to T directly. Within f2 , there's no T to refer to, but I can get the same effect using decltype : auto f2 = [](auto parameter) { using T = decltype(param); ... }; An advantage of the generic lambda is that I can perfect-forward it. I can't do that with the function template: template<typename T> void fwdToG(T&& param) { g(std::forward<T>(param)); } fwdToG(f1); // error! fwdToG(f2); // okay Are there

As far as I understand - generic lambdas are transformed into objects of local scope structs with templated operator() . This makes generic lambda very powerful and easy to use tool. On the other hand one can create structs nested into the function, when however the struct has templated member e.g.: #include <iostream> int main() { struct inner { template <class T> void operator()(T &&i) { } }; return 0; } or is templated by itself: int main() { template <class T> struct inner { void operator()(T &&i) { } }; return 0; } compiler seems to have a problem with compiling it: error: invalid

Consider this pseudo-snippet: class SomeClass { public: SomeClass() { if(true) { fooCall = [](auto a){ cout << a.sayHello(); }; } else { fooCall = [](auto b){ cout << b.sayHello(); }; } } private: template<typename T> std::function<void(T)> fooCall; }; What I want is a class member fooCall which stores a generic lambda, which in turn is assigned in the constructor. The compiler complains that fooCall cannot be a templated data member. Is there any simple solution on how i can store generic lambdas in a class? There is no way you'll be able to choose between two generic lambdas at run-time, as

I have installed Code::Blocks for Windows and want to compile C++14 code like generic lambdas but the binary version of Code::Blocks that I've installed from codeblocks.org doesn't support the flag -std=c++14 . How do I update the compiler and enable -std=c++14 flag for Code::Blocks? Andreas DM To compile your source code using C++14 in Code::Blocks, you, first of all, need to download and install a compiler that supports C++14 features. Here’s how you can do it on Windows: Download MinGW from here (particular build) or from official site to choose options Extract it to for example: C:\