我已经使用 C++ 模板开发了一个数组库来处理许多类型 {int、float、double}。我将结构和函数的定义和声明存储在文件 Util.h 和 Util.cpp 中。我在arraySample.cpp 中调用它。但是,我无法编译该项目。g++ 说对 printArray 的未定义引用
错误信息
make all
g++ -O2 -g -Wall -fmessage-length=0 -c -o arraySample.o arraySample.cpp
g++ -O2 -g -Wall -fmessage-length=0 -c -o Util.o Util.cpp
g++ -o arraySample arraySample.o Util.o
arraySample.o: In function `main':
/home/vtvan/Desktop/workspace/arraySample/arraySample.cpp:15: undefined reference to `int printArray<double>(Array<double>)'
/home/vtvan/Desktop/workspace/arraySample/arraySample.cpp:22: undefined reference to `int printArray<int>(Array<int>)'
collect2: ld returned 1 exit status
make: *** [arraySample] Error 1
请帮我解决这个问题,我尝试了很多次但无法解决。很奇怪,当我将3个文件组合在一起时,它可以很好地工作。所以请给我一些解决方案。我在这里附上3个文件的源代码供您参考。
非常感谢您,我期待您的回复。
实用程序.h
#ifndef UTIL_H_
#define UTIL_H_
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <typeinfo>
#define ARRAYMAXNDIMS 3
// multi-dimensional array
template <typename T>
struct Array {
T *x;
int size;
int nDims;
int N[ARRAYMAXNDIMS];
};
template <typename T> int printArray(Array<T> A);
#endif /* UTIL_H_ */
实用程序.cpp
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <typeinfo>
#include "Util.h"
template <typename T> int printArray(Array<T> A) {
int i = 0, j = 0;
int k,l;
std::string typeT = typeid(T).name();
std::string format(" %9f");
if (!typeT.compare("i"))
format = " %d";
printf("Array with dimension (%d",A.N[0]);
k=1;
while(k<A.nDims && k<ARRAYMAXNDIMS){
printf(",%d",A.N[k]);
k++;
}
printf(")\n");
switch (A.nDims) {
case 1: // print 1D array
for(k=0;k<A.N[0];k++){ printf(" %9d",A.x[k]);}
printf("\n");
return(1);
case 2: // print 2D array
for(k=0;k<A.N[0];k++){
for(l=0;l<A.N[1];l++) {
printf(format.c_str(),A.x[k+l*A.N[0]]);
}
printf("\n");
}
return(1);
case 3: // print last 2 dimensions of a 3D array, where the index of the first dimension is i
if(i<0 || i>=A.N[0]) {
printf("index %d is outside the range of indices for the first dimension, i.e. [0:%d]\n",i,A.N[0]-1);
return(0);
}
printf("printing slice (%d,:,:)\n",i);
for(k=0;k<A.N[1];k++){
// printf("%5d ",k);
for(l=0;l<A.N[2];l++) printf(" %9d",A.x[i+k*A.N[0]+l*A.N[0]*A.N[1]]);
printf("\n");
}
return(1);
}
}
数组样本.cpp
#include <stdio.h>
#include <stdlib.h>
#include "Util.h"
int main(void) {
Array<double> a;
a.nDims = 2; a.N[0] = 2; a.N[1] = 2; a.size = 4;
a.x = (double *)calloc(a.size,sizeof(double));
a.x[0] = 1.23; a.x[1] = 2.23; a.x[2] = 3.23; a.x[3] = 5.23;
printArray(a);
Array<int> b;
b.nDims = 2; b.N[0] = 2; b.N[1] = 2; b.size = 4;
b.x = (int *)calloc(b.size,sizeof(int));
b.x[0] = 1; b.x[1] = 2; b.x[2] = 3; b.x[3] = 5;
printArray(b);
return 0;
}