c语言有多个重载函数fabs,c ++-对abs（double）的模棱两可的重载调用

我有以下C ++代码：

#include

#include // per http://www.cplusplus.com/reference/clibrary/cmath/abs/

// snip ...

if ( (loan_balance < 0) && (abs(loan_balance) > loan_payment) ) {

...

}

和make爆炸：

error: call of overloaded 'abs(double)' is ambiguous

也感兴趣：

/usr/include/stdlib.h:785: note: candidates are: int abs(int)

如何指定编译器需要在cmath.h中调用可以处理浮点数的abs()？

编译器信息(不确定是否重要)：

[some_man@some_box ~/some_code]# gcc -v

Using built-in specs.

Target: i386-redhat-linux

Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr /share/info --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-libgcj-multifile --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk --disable-dssi --enable-plugin --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --with-cpu=generic --host=i386-redhat-linux

Thread model: posix

gcc version 4.1.2 20080704 (Red Hat 4.1.2-44)