Annex G (informative) Ill-formed, no diagnostic required [ifndr]

G.10 [temp]: Templates [ifndr.temp]

G.10.13[ifndr:temp.expl.spec.missing.definition]
Specified in: [temp.expl.spec]

1
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If an explicit specialization of a template is declared but there is no definition provided for that specialization, the program is ill-formed, no diagnostic required.
2
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[Example 1: template <typename T> int f(T&&) { return 0; } template <> int f<int>(int&&); int j = f(1); // IFNDR, odr-use of f<int> with no definition — end example]