If you start with a string literal, then the form:<div><br></div><div>vtkErrorMacro("string")</div><div><br></div><div>or</div><div><br></div><div>vtkErrorMacro("string" << variable << ", " << more_stuff);</div>
<div><br></div><div>works fine. If you need to start with a variable, then to effectively put the "<<" before the "x" in your example, you need to start with "<<":</div><div><br></div>
<div>vtkErrorMacro(<< fname << " invalid");</div><div><br></div><div>Indeed, not starting with "<<" is a shortcut that only works with string literals. Many places in VTK start the error macro with "<<" when needed.</div>
<div><br></div><div>Jeff<br><br><div class="gmail_quote">On Sat, Nov 20, 2010 at 7:27 PM, Mark Roden <span dir="ltr"><<a href="mailto:mmroden@gmail.com">mmroden@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
I should add, this is with visual studio 2008 on a windows 7 machine, 64 bit compiler.<div><div></div><div class="h5"><br><br><div class="gmail_quote">On Sat, Nov 20, 2010 at 4:13 PM, Mark Roden <span dir="ltr"><<a href="mailto:mmroden@gmail.com" target="_blank">mmroden@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204, 204, 204);padding-left:1ex">Hi all,<br><br>I'm having a problem with the vtk error macro, and was hoping someone could shed some light on the issue.<br>
<br>The relevant lines for this problem start on line 467 of vtkGetSet.h from the git head:<br>
<br> vtkmsg << "ERROR: In " __FILE__ ", line " << __LINE__ \<br> << "\n" << self->GetClassName() << " (" << self \<br>
<< "): " x << "\n\n"; \<br><br>If x is a std::string, the above fails to compile, but the following is fine:<br><br> vtkmsg << "ERROR: In " __FILE__ ", line " << __LINE__ \<br>
<< "\n" << self->GetClassName() << " (" << self \<br> << "): " << x << "\n\n"; \<br>
<br>Note the extra << right before x.<br><br>I'm doing this to debug a problem in the vtkGDCMImageReader I'm having where images aren't being read in Java, but are read just fine in C++-- I think that there's a problem with string termination, but I don't know. So, I want to add the filename to the debug message.<br>
<br>The lines in gdcm are:<br><br> if( !reader.Read() )<br> {<br> //added more detail for those instances where you can't debug, like in java<br> std::string theFilename(filename);<br> std::string theError = "ImageReader failed on file: " + theFilename;<br>
vtkErrorMacro( theError );<br> return 0;<br> }<br><br>and they were:<br><br> if( !reader.Read() )<br> {<br> vtkErrorMacro( "ImageReader failed" );<br> return 0;<br> }<br><br>I don't want to change vtk at all, I want to use what exists. I could just modify my version right now to make my error message work (or at least compile)-- but how should I use the warning/error macros to get more information out than just a pure const char*? I tried to use theError.c_str(), but that also failed. It also failed to compile if I just sent filename over directly, as in vtkErrorMacro(filename);<br>
<br>Thanks,<br><font color="#888888">Mark<br><br>
</font></blockquote></div><br>
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