Strange compilation error : undefined reference to ...

[pl01]

Hi,

I'm using QT Creator 2.1 under Win7 and with the following code I got this error :

error: undefined reference to `File::file_exists(QString const&) const'

The code

if ( _myfile.file_exists("test.txt") )

if ( _myfile.file_exists("test.txt") )

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The class code

bool file_exists(const QString & file) const;

bool file_exists(const QString & file) const;

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I have the same problem with other files, by example

FinancialCategory* category = ...;
Product::get( category );
 
...
 
namespace Product {
  bool get(Category* c)
}

FinancialCategory* category = ...;
Product::get( category );

...

namespace Product {
  bool get(Category* c)
}

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And I got this error : error: undefined reference to `Product::get(FinancialCategory* c)'

If I do the following it works Product::get((Category*) category ) ... but it should be handled automatically ?

Thanks for your help