docs: improve the prose describing _AC_CHECK_TYPE_NEW_BODY

* lib/autoconf/types.m4 (_AC_CHECK_TYPE_NEW_BODY): Improve prose.

diff --git a/ChangeLog b/ChangeLog
index 1e17e609000b597383c228c593d19da4e04bf62c..219176f8ee629bffa73256789b8e8561c231629f 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2011-07-24  Jim Meyering  <meyering@redhat.com>
+
+       docs: improve the prose describing _AC_CHECK_TYPE_NEW_BODY
+       * lib/autoconf/types.m4 (_AC_CHECK_TYPE_NEW_BODY): Improve prose.
+
 2011-08-31  Paul Eggert  <eggert@cs.ucla.edu>
 
        AC_C_CONST: don't reject gcc -Werror -Wall

diff --git a/lib/autoconf/types.m4 b/lib/autoconf/types.m4
index c47884c5a1873d610c16cad26e69fade2fb81cf1..72093e994b08e8064ee83fa7374e70284eed039e 100644 (file)
--- a/lib/autoconf/types.m4
+++ b/lib/autoconf/types.m4
@@ -80,15 +80,15 @@
 #        int foo (TYPE param);
 #
 # but of course you soon realize this does not make it with K&R
-# compilers.  And by no ways you want to
+# compilers.  And by no means do you want to use this:
 #
 #        int foo (param)
 #          TYPE param
 #        { ; }
 #
-# since this time it's C++ who is not happy.
+# since C++ would complain loudly.
 #
-# Don't even think of the return type of a function, since K&R cries
+# Don't even think of using a function return type, since K&R cries
 # there too.  So you start thinking of declaring a *pointer* to this TYPE:
 #
 #        TYPE *p;
@@ -101,14 +101,16 @@
 #
 #        sizeof (TYPE);
 #
-# But this succeeds if TYPE is a variable: you get the size of the
-# variable's type!!!
+# That is great, but has one drawback: it succeeds when TYPE happens
+# to be a variable: you'd get the size of the variable's type.
+# Obviously, we must not accept a variable in place of a type name.
 #
-# So, to filter out the last possibility, you try this too:
+# So, to filter out the last possibility, we will require that this fail:
 #
 #        sizeof ((TYPE));
 #
-# This fails if TYPE is a type, but succeeds if TYPE is actually a variable.
+# This evokes a syntax error when TYPE is a type, but succeeds if TYPE
+# is actually a variable.
 #
 # Also note that we use
 #