re PR c++/4025 (Document use/non-use of -fno-implicit-templates in bootflags)

2018-11-17  Sandra Loosemore  <sandra@codesourcery.com>

	PR c++/4025

	gcc/
	* doc/invoke.texi (C++ Dialect Options): Clarify usage of
	-fno-implicit-templates.

From-SVN: r266239

gcc/ChangeLog

+2018-11-17  Sandra Loosemore  <sandra@codesourcery.com>
+
+	PR c++/4025
+	* doc/invoke.texi (C++ Dialect Options): Clarify usage of
+	-fno-implicit-templates.
+
 2018-11-17  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/87546

gcc/doc/invoke.texi

@@ -2574,6 +2574,9 @@ This option is implied by the strict ISO C++ dialects: @option{-ansi},
 @opindex fimplicit-templates
 Never emit code for non-inline templates that are instantiated
 implicitly (i.e.@: by use); only emit code for explicit instantiations.
+If you use this option, you must take care to structure your code to
+include all the necessary explicit instantiations to avoid getting
+undefined symbols at link time.
 @xref{Template Instantiation}, for more information.
 
 @item -fno-implicit-inline-templates