[PATCH] Add nodiscard to std::vector::empty()

[Jonathan Wakely]

We already added it to the std::vector primary template.

        * include/bits/stl_bvector.h (vector<bool>::empty()): Add nodiscard
        attribute.

Tested powerpc64le-linux, committed to trunk.


commit 42dd15d09edbdafbeb068b9b2191e459b9df1b82
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Mon Apr 29 13:23:54 2019 +0100

    Add nodiscard to std::vector<bool>::empty()
    
    We already added it to the std::vector primary template.
    
            * include/bits/stl_bvector.h (vector<bool>::empty()): Add nodiscard
            attribute.

diff --git a/libstdc++-v3/include/bits/stl_bvector.h 
b/libstdc++-v3/include/bits/stl_bvector.h
index 294f1e42897..c60f4f0ef1c 100644
--- a/libstdc++-v3/include/bits/stl_bvector.h
+++ b/libstdc++-v3/include/bits/stl_bvector.h
@@ -878,7 +878,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       { return size_type(const_iterator(this->_M_impl._M_end_addr(), 0)
                         - begin()); }
 
-      bool
+      _GLIBCXX_NODISCARD bool
       empty() const _GLIBCXX_NOEXCEPT
       { return begin() == end(); }