header-files

问题 I have the following declarations FILE *fptr; FILE *optr; in algo.h I have the main in main.c which opens these files. I get the above error if I put the declarations in the header file. If I put it in the main.c, then I get mutiple definition errors like src\main.o:main.c:(.bss+0xc88): multiple definition of rcount' src\new_algo.o:new_algo.c:(.bss+0xc88): first defined here src\main.o:main.c:(.bss+0xc8c): multiple definition of condi' src\new_algo.o:new_algo.c:(.bss+0xc8c): first defined

问题 Take this file as example,there are many non-extern structures like: struct list_head source_list; How can it work when this header file is included by more than one compile units? There should be error reporting that the same symbol is defined twice,right? 回答1: Technically there should, but that usage has been around for years and is impossible to eradicate (it's been tried; every so often some vendor decides to make it an error, and reverts after the first hundred or so bug reports).

问题 I am looking at a library on github which has the following in one of the header files: class Util { public: static void log( const string& message ); static void log( const char* message ); template<typename T> static inline string toString(T t) { stringstream s; s << t; return s.str(); } }; and the following in the source file: void Util::log( const string& message ) { const string& logMessage = "[cppWebSockets] " + message; syslog( LOG_WARNING, "%s", logMessage.c_str( ) ); } void Util::log

问题 I am using Visual C++ 2010 Express. I have a form ( Form1.h ) that contains a button ( btn1 ) and a label ( label1 ). When I click the button, I would like to call a function from a different header file ( testing.h ) that will then proceed to change the text in the label. What I have is something like this... Form1.h #include "testing.h" ... standard form code generated by Visual Studio private: System::Windows::Forms::Label^ label1; ... private: System::Void btn1_Click(System::Object^

问题 I can't get my head around headers and header guards. I've read other questions and their answers but I still can't make this work in Visual Studio 2013: main.cpp #include "stdafx.h" #include <iostream> #include "add.h" int _tmain(int argc, _TCHAR* argv[]) { std::cout << "3 + 4 = " << add(3, 4) << std::endl; system("pause"); return 0; } add.cpp #include "stdafx.h" //ADDED LATER; NOW WORKING (AND SEE QUESTION 2 BELOW) #include "add.h" //ADDED LATER; NOR WORKING (AND SEE QUESTION 2 BELOW) int

问题 Where can I find my C header files on unixOS.Please kindly give me your inputs. 回答1: GCC looks in several different places for headers. On a normal Unix system, if you do not instruct it otherwise, it will look for headers requested with #include in: /usr/local/include libdir/gcc/target/version/include /usr/target/include /usr/include 来源： https://stackoverflow.com/questions/14470985/where-can-i-find-header-files-in-c-on-unix

问题 This is my first time tackling a CUDA project that's slightly more complex than the simple write-single-source-file-and-compile routine. As expected, I'm facing some issues with C headers, namely duplicated symbols. According to the linker, conflicts arise over the inclusion of the following header file in multiple .cu files: env_vars.h #ifndef ENV_VARS_H_ #define ENV_VARS_H_ /*** GLOBAL VARIABLES ***/ unsigned int h_n_osc; __device__ unsigned int d_n_osc; /*** CONSTANTS ***/ const double

问题 I'm using pod chronotruck/FlagPhoneNumber I just updated from High Sierra/Xcode 10.1/Swift 4.2/Cocoapoods v-1.5.3 to Mojave 10.14.15/Xcode 10.2.1/Swift 5/Cocoapoods v-1.7.3 and I can't build because inside the NBRegExMatcher.m file I get the error 'NBPhoneNumberDesc.h' file not found Everything worked fine before the upgrade and I never had any of these errors. The Podfile.lock has this inside of it: - FlagPhoneNumber (0.7.6): - FlagPhoneNumber/libPhoneNumberiOS (= 0.7.6) - FlagPhoneNumber

问题 Qt Creator 4.2.1 The editor in this IDE can be split. It would be nice if header and source files will be load into those two after (for example) double clicking on project tree. Do you know any way, maybe a plugin for this? Now I am using F4 for switching between source and header. It also would be nice to see only one item in project tree for header-source pair - it would take less place. 来源： https://stackoverflow.com/questions/44384708/qt-creator-split-editor-for-source-and-header

问题 While compiling a C program in LINUX, I get the foll. error: stream.h:1123: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'int' stream.h:1124: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'mblk_t' stream.h:1125: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'mblk_t' Line 1123,1124 and 1125 are given below: __STREAMS_EXTERN int adjmsg(mblk_t *mp, register ssize_t length); __STREAMS_EXTERN mblk_t *allocb(size_t size, unsigned int priority); _