Doc tweak

[Marc Glisse]

Hello,

someone got confused by the text saying that all the GMP declarations are 
in gmp.h and thought the C++ class interface would be there as well, so 
I'll probably add this patch unless someone has a better proposition.

(shell seems to be missing some packages to build the doc in ps or pdf)

--- a/doc/gmp.texi      Tue Nov 02 02:02:59 2021 +0100
+++ b/doc/gmp.texi      Sat Nov 06 13:32:05 2021 +0100
@@ -1860,7 +1860,9 @@
  @cindex Include files
  @cindex @code{#include}
  All declarations needed to use GMP are collected in the include file
- at file{gmp.h}.  It is designed to work with both C and C++ compilers.
+ at file{gmp.h}, except for the @ref{C++ Class Interface} which comes with its
+own separate header @file{gmpxx.h}.  @file{gmp.h} is designed to work with
+both C and C++ compilers.

  @example
  #include <gmp.h>
@@ -1868,7 +1870,7 @@

  @cindex @code{stdio.h}
  Note however that prototypes for GMP functions with @code{FILE *} parameters
-are only provided if @code{<stdio.h>} is included too.
+are only provided if @code{<stdio.h>} is included before.

  @example
  #include <stdio.h>
@@ -1892,9 +1894,10 @@
  @end example

  @cindex @code{libgmpxx}
-GMP C++ functions are in a separate @file{libgmpxx} library.  This is built
-and installed if C++ support has been enabled (@pxref{Build Options}).  For
-example,
+GMP C++ functions are in a separate @file{libgmpxx} library, including the
+ at ref{C++ Class Interface} but also @ref{C++ Formatted Output} for regular
+GMP types.  This is built and installed if C++ support has been enabled
+(@pxref{Build Options}).  For example,

  @example
  g++ mycxxprog.cc -lgmpxx -lgmp


-- 
Marc Glisse