C++ 如何在c+;中使用友元函数时避免访问错误+;?
C++ 如何在c+;中使用友元函数时避免访问错误+;?,c++,friend,access-specifier,C++,Friend,Access Specifier,boss中的friend total(boss,employe)声明失败,因为employe尚未声明 在boss上方添加employe的转发声明 16:31:40 **** Incremental Build of configuration Debug for project Practice **** make all 'Building file: ../src/Practice.cpp' 'Invoking: Cross G++ Compiler' g++ -O0 -g
boss
中的friend total(boss,employe)
声明失败,因为employe
尚未声明
在boss
上方添加employe
的转发声明
16:31:40 **** Incremental Build of configuration Debug for project Practice ****
make all
'Building file: ../src/Practice.cpp'
'Invoking: Cross G++ Compiler'
g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/Practice.d" -MT"src/Practice.o" -o "src/Practice.o" "../src/Practice.cpp"
../src/Practice.cpp:20:26: error: 'employe' has not been declared
20 | friend void total(boss, employe);
| ^~~~~~~
../src/Practice.cpp: In function 'void total(boss, employe)':
../src/Practice.cpp:38:8: error: 'int boss::salary' is private within this context
38 | T = b.salary + e.salary;
| ^~~~~~
../src/Practice.cpp:13:6: note: declared private here
13 | int salary = 3000;
| ^~~~~~
make: *** [src/subdir.mk:20: src/Practice.o] Error 1
"make all" terminated with exit code 2. Build might be incomplete.
16:31:40 Build Failed. 3 errors, 0 warnings. (took 655ms)
class雇员;//您需要employe类的转发声明。
16:31:40 **** Incremental Build of configuration Debug for project Practice ****
make all
'Building file: ../src/Practice.cpp'
'Invoking: Cross G++ Compiler'
g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/Practice.d" -MT"src/Practice.o" -o "src/Practice.o" "../src/Practice.cpp"
../src/Practice.cpp:20:26: error: 'employe' has not been declared
20 | friend void total(boss, employe);
| ^~~~~~~
../src/Practice.cpp: In function 'void total(boss, employe)':
../src/Practice.cpp:38:8: error: 'int boss::salary' is private within this context
38 | T = b.salary + e.salary;
| ^~~~~~
../src/Practice.cpp:13:6: note: declared private here
13 | int salary = 3000;
| ^~~~~~
make: *** [src/subdir.mk:20: src/Practice.o] Error 1
"make all" terminated with exit code 2. Build might be incomplete.
16:31:40 Build Failed. 3 errors, 0 warnings. (took 655ms)
class employe; // <--- add this
class boss{
int salary = 3000;
public:
boss();
boss(int b){
salary = b;
}
friend void total(boss, employe);
};