Compiler Error C3749

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'attribute': a custom attribute may not be used inside a function

A custom attribute cannot be used inside a function. (For more information on custom attributes, see the topic attribute.)

The following sample generates C3749:

// C3749a.cpp
// compile with: /clr /c
using namespace System;

[AttributeUsage(AttributeTargets::All)]
public ref struct ABC : public Attribute {
   ABC() {}
};

void f1() { [ABC]; };  // C3749

The following sample generates C3749:

// C3749b.cpp
// compile with: /clr:oldSyntax /c
using namespace System;

[attribute(All)]
public __gc struct ABC {
   ABC() {}
};

void f1() { [ABC]; };  // C3749