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Failing to set arrize size with var

dhume878 (4)
Hey guys,

Thanks up front for your help, this seems like a ridiculous problem but I'm stuck on it (drat!).

Anyway, I have a structure and I'm trying to create a string array in the following way.

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// Populate Structure
cfile.frames = atoi(calHeader[0][1].c_str()); 
cfile.cameras = atoi(calHeader[1][1].c_str());
cfile.markers = atoi(calHeader[2][1].c_str());
cfile.frequency = atoi(calHeader[3][1].c_str());
		
// Create String Array with length of # of markers
string mNames[cfile.markers];


I get the following errors:
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error C2057: expected constant expression
error C2466: cannot allocate an array of constant size 0
error C2466: cannot allocate an array of constant size 0


I can print out the value in cfile.markers, it's 52.
I then thought, hm maybe it needs a constant int.

So I tried:

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const int SIZE = cfile.markers;
string mNames[SIZE];


Still no luck. I'm failing on the instantiation of the array. The following works:

string mNames[52];

works just fine.


Here is the whole function:
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struct calFile {
  int frames, cameras, markers, frequency;
}; calFile cfile;

void ReadCalFile(void)
{
	ifstream calFile("SC0046.tsv", ios::in);
	
	if (calFile.is_open())
	{

		cout << "File Opened!\n";

		stringstream iss;
		string line, word;
		string calHeader[9][3];
		int i=0,j=0;

		// Read in cal header file, and fill array.
		// Next: Str2num and add to calfile Struct
		while (getline(calFile,line))
		{
			if(i==9) {break;}
			iss << line;

			while (getline(iss,word,'\t')) {
				if(i==7) {
					if(j==3) {break;}
					calHeader[i][j]=word;

				} else {
					if(j==2) {break;}
					calHeader[i][j]=word;	
				}
				j++;
			}

			j=0;
			iss.clear();
			i++;
		}

		// Populate Structure
		cfile.frames = atoi(calHeader[0][1].c_str()); 
		cfile.cameras = atoi(calHeader[1][1].c_str());
		cfile.markers = atoi(calHeader[2][1].c_str());
		cfile.frequency = atoi(calHeader[3][1].c_str());
		
		// Pull Marker Names
		const int SIZE = cfile.markers;
		string mNames[SIZE];
                //string mNames[cfile.markers];
		//getline(calFile,line);
		cout << SIZE << endl;
		
		// Close file
		calFile.close();

	} else {cout << "File did not open\n";}


}


I'm using VS2010 and including <string>.

Thanks again.
moorecm (1932)
To specify the size of an array at runtime you have to use dynamic memory allocation. A std::vector is one possible approach:
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#include <vector>
//...

// create a vector of strings (with length of # of markers)
std::vector< std::string > mNames( cfile.markers );
dhume878 (4)
Okay, thanks a lot moorecm.
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