[glibmm] gmmproc: _CLASS_BOXEDTYPE: Make the static swap() noexcept.

[Murray Cumming <murrayc src gnome org>]

commit 767bc5c42eecd815a193043175d16fb9b437ee3a
Author: Murray Cumming <murrayc murrayc com>
Date:   Sat Aug 22 12:40:30 2015 +0200

    gmmproc: _CLASS_BOXEDTYPE: Make the static swap() noexcept.
    
    This is generally a good idea because it lets standard containers
    use the swap() while maintaining their own noexcept.
    
    This would not be an ABI break, hopefully, because this is an inline
    method in the header anyway.
    We have recently added the noexcept to the member swap() method,
    but hopefully that is not an ABI break either. Removing noexcept
    would be an ABI break, I think.

 tools/m4/class_boxedtype.m4 |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/tools/m4/class_boxedtype.m4 b/tools/m4/class_boxedtype.m4
index 3df7f69..2af2a13 100644
--- a/tools/m4/class_boxedtype.m4
+++ b/tools/m4/class_boxedtype.m4
@@ -61,7 +61,7 @@ __NAMESPACE_BEGIN__
  * @param lhs The left-hand side
  * @param rhs The right-hand side
  */
-inline void swap(__CPPNAME__& lhs, __CPPNAME__& rhs)
+inline void swap(__CPPNAME__& lhs, __CPPNAME__& rhs) noexcept
   { lhs.swap(rhs); }
 
 __NAMESPACE_END__