temporary

问题 Slightly related to this question I'd like to work with a temporary branch in a shell script. somewhat along the lines of : cd $(git rev-parse --show-toplevel) && git subtree split --prefix=some_subfolder -b temp && git push my_remote temp:publication_branch -f Now, I'm not sure what this will do if the branch temp already exists, in any case I don't want the result on my_remote/publication_branch to depend on that. And I also don't want to modify the branch temp (assuming I have it for

问题 My question (which will follow after this, sorry about the long intro, the question is down there in bold ) is originally inspired by Item 23 in Herb Sutters Exceptional C++ where we find something like this: <snip> ... int main() { GenericTableAlgorithm a( "Customer", MyWorker() ); a.Process(); } with class GenericTableAlgorithm { public: GenericTableAlgorithm( const string& table, GTAClient& worker ); bool Process(); private: struct GenericTableAlgorithmImpl* pimpl_; //implementation };

问题 After reading this answer from ildjarn, I wrote the following example, and it looks like an unnamed temporary object has the same life time as its reference! How come this is possible? Is it specified in the C++ standard? Which version? Source code: #include <iostream> //cout #include <sstream> //ostringstream int main () { std::ostringstream oss; oss << 1234; std::string const& str = oss.str(); char const* ptr = str.c_str(); // Change the stream content oss << "_more_stuff_"; oss.str(""); /

问题 I get the fortran runtime warning "An array temporary was created" when running my code (compiled with gfortran) and I would like to know if there is a better way to solve this warning. My original code is something like this: allocate(flx_est(lsign,3)) allocate(flx_err(lsign,3)) do i=1,lsign call combflx_calc(flx_est(i,:),flx_err(i,:)) enddo Inside the subroutine I define the variables like this: subroutine combflx_calc(flx_est,flx_err) use,intrinsic :: ISO_Fortran_env, only: real64 implicit

问题 I have a special type of ostringstream that I am trying to output text to as a temporary object but I'm having some trouble. To be clear, this is essentially what I want to do: ostringstream() << "PARTY DOWN!" << endl; Now before you say: "But Zack, that code is totally worthless! The object is destroyed at the end of the line, how would you even know if it did anything?", hear me out. I don't try to do this with plain ostringstreams, but rather a derived class in which the destructor

问题 I tried following code : #include<iostream> #include<string> using namespace std; string f1(string s) { return s="f1 called"; } void f2(string *s) { cout<<*s<<endl; } int main() { string str; f2(&f1(str)); } But this code doesn't compile. What I think is : f1 returns by value so it creates temporary, of which I am taking address and passing to f2. Now Please explain me where I am thinking wrong? 回答1: The unary & takes an lvalue (or a function name). Function f1() doesn't return an lvalue, it

问题 The code is as follows: #include <iostream> using namespace std; class A { }; A rtByValue() { return A(); } void passByRef(A &aRef) { // do nothing } int main() { A aa; rtByValue() = aa; // compile without errors passByRef(rtByValue()); // compile with error return 0; } The g++ compiler gives the following error: d.cpp: In function ‘int main()’: d.cpp:19:23: error: invalid initialization of non-const reference of type ‘A&’ from an rvalue of type ‘A’ d.cpp:12:6: error: in passing argument 1 of

问题 Why is it not allowed to get non-const reference to a temporary object, which function getx() returns? Clearly, this is prohibited by C++ Standard but I am interested in the purpose of such restriction, not a reference to the standard. struct X { X& ref() { return *this; } }; X getx() { return X();} void g(X & x) {} int f() { const X& x = getx(); // OK X& x = getx(); // error X& x = getx().ref(); // OK g(getx()); //error g(getx().ref()); //OK return 0; } It is clear that the lifetime of the

问题 We are creating temp table in procedures and we use no persistent connection for mysql. There are many temp tables is increasing slowly after mysql restart and then the innodb_buffer_pool_size is finishing. The application is working on this server; CPU E3-1245 v5 @ 3.50GHz - 8 core 16GB Ram The image shows tmp tables how increasing is: My.cnf: [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock skip_name_resolve join_buffer_size = 4M sort_buffer_size = 1M read_rnd_buffer_size =

问题 I am creating a new website, and it's already online, but I want to block access to everyone! And just let my client use it to check the development process everyday, so he don't need to download everything and set up on his computer.. I was wondering about using ASP Identity, is there any simple "hack" to achieve this? Or my only way is the following: Add the Register Page to the WebSite Register an account with Administrator role Delete Register Page of the WebSite Use always the same