Compiler Warning (level 3) C4980
'keyword' : use of this keyword requires /clr:oldSyntax command line option
A keyword from a previous version was used. Update your code to use newer syntax, or use /clr:oldSyntax. For more information about the newer syntax, see Component Extensions for Runtime Platforms.
C4980 is a warning that is always issued as an error. Use /wd to turn the warning off. See /w, /Wn, /WX, /Wall, /wln, /wdn, /wen, /won (Warning Level) for more information.
The following sample generates C4980:
// C4980.cpp
// compile with: /clr
int main() {
int x1 = 0;
int^ px = __box(x1); // C4980
int^ px2 = x1; // OK
}