Conflicting declarations

Unless otherwise specified, two declarations cannot (re)introduce the same entity. The program is ill-formed if such declarations exist.

# Defect reports

DRApplied toBehavior as publishedCorrect behavior
CWG 279(P1787R6)C++98it was unclear whether an unnamed class or enumeration canbe redeclared if it has a typedef name for linkage purposesit can be redeclared
CWG 338(P1787R6)C++98it was unclear whether an unnamed enumeration can beredeclared if it has an enumerator as a name for linkage purposesit can be redeclared
CWG 1884(P1787R6)C++98the restrictions applied to multipledeclarations of the same entity were unclearmade clear