c++ - multiple definition of #define function -


i have logger.h file , defining macro function logging:

//logger.h: #ifndef _logger_h_ #define _logger_h_  #ifdef log_debug     ofstream debug_log("debug.log");     #define log(...) debug_log << __file__ << ":" << __pretty_function__ << ":" << __line__ << "| " << __va_args__ << std::endl #else     #define log(...) #endif  #endif

this header file included in multiple c files. , using log() function. g++ giving:

/tmp/ccmajysm.o:(.bss+0x0): multiple definition of `debug_log' /tmp/cchj3w7u.o:(.bss+0x0): first defined here /tmp/cc3lq9gq.o:(.bss+0x0): multiple definition of `debug_log' /tmp/cchj3w7u.o:(.bss+0x0): first defined here

any clue?

if declared log_debug @ project-level (or in multiple translation units), see 

ofstream debug_log("debug.log");

line , you'll have multiple definitions.

a possible solution: put single translation unit while rendering others aware of existence

header

#ifndef _logger_h_ #define _logger_h_  #ifdef log_debug     extern ofstream debug_log;     #define log(...) debug_log << __file__ << ":" << __pretty_function__ << ":" << __line__ << "| " << __va_args__ << std::endl #else     #define log(...) #endif  #endif

a cpp file

ofstream debug_log("debug.log");

Comments

Post a Comment

Popular posts from this blog

c++ - Difference between pre and post decrement in recursive function argument -

i have following sample code used pre-decrement void function(int c) { if(c == 0) { return; } else { cout << "dp" << c << endl; function(--c); cout << c << endl; return; } } this function give output input 4 : dp3 dp2 dp1 dp0 0 1 2 3 but when use post decrement void function(int c) { if(c == 0) { return; } else { cout << "dp" << c << endl; function(c--); cout << c << endl; return; } } output goes in infinite loop dp4 can explain me in detail why happens ? this happens because function(c--) called same value of c , when finishes c decremented. recursively called, hence called same value no chance of return , hit stack overflow error. assume this, int x = 1, y = 0; y = x++ result y == 1 , x == 2. if y = ++x , bot x , y 2.
Read more

php - Nothing but 'run(); ' when browsing to my local project, how do I fix this? -

i added new project. made mistake in projectname.conf file in sites-available apache2, led me reinstalling apache2. after reinstalling , re-enabling projects on every page of every project .. <body> run(); </body> .. i've run composer update, restarted service, restarted pc, checked config files, tried disabling new project. there nothing in error log, , access.log: 127.0.0.1 - - [15/may/2015:01:40:47 +0200] "get / http/1.1" 304 181 "-" "mozilla/5.0 (x11; ubuntu; linux x86_64; rv:38.0) gecko/20100101 firefox/38.0" maybe i'm forgetting apache2 reinstall? don't think did different last time installed it. looks haven't setup php correctly. take @ this great guide , maybe you're forgetting link php config apache2.
Read more

php - How can I echo out this array? -

i don't know how go grabbing data in variable , put foreach loop. class tree{ private $info = array( array('name'=>'jim','state'=>'nu','company'=>'nu','phone'=>array('cell'=>'5615111111','office'=>'5611111111'),'email'=>array('primary'=>'exs@example.com','ex@there.com')), array('name'=>'joe smith','city'=>'phoenix','phone'=>'4805551111','email'=>'jsmith@some_email.com'), array('name'=>'john doe','city'=>'chandler','company'=>'doe co.','email'=>array('jdoe@gmail.com','personal'=>'email@email.com'),'phone'=>'6025550002') ); } if you're inside of class, can access private variable using $this->variablename . example, i
Read more