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| -rw-r--r-- | docs/users_guide/glasgow_exts.xml | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/docs/users_guide/glasgow_exts.xml b/docs/users_guide/glasgow_exts.xml index 4ed8c2aae3..61cff6ecf2 100644 --- a/docs/users_guide/glasgow_exts.xml +++ b/docs/users_guide/glasgow_exts.xml @@ -381,6 +381,13 @@ worse, the unboxed value might be larger than a pointer (<literal>Double#</literal> for instance). </para> </listitem> +<listitem><para> You cannot define a newtype whose representation type +(the argument type of the data constructor) is an unboxed type. Thus, +this is illegal: +<programlisting> + newtype A = MkA Int# +</programlisting> +</para></listitem> <listitem><para> You cannot bind a variable with an unboxed type in a <emphasis>top-level</emphasis> binding. </para></listitem> |