Kenlm build failed with error C2678

[LilyWangL]

I am a member of Microsoft VCPKG team. In an internal version of Visual Studio, kenlm build failed with error C2678:

E:\repro\binaries.amd64ret\inc\algorithm(7280): error C2678: binary '=': no operator found which takes a left-hand operand of type 'const Proxy' (or there is no acceptable conversion)
        with
        [
            Proxy=lm::ngram::trie::`anonymous-namespace'::PartialViewProxy
        ]
E:\1102\vcpkg\buildtrees\kenlm\src\2b1d91de6b-8796a520fb.clean\lm\trie_sort.cc(47): note: could be 'lm::ngram::trie::`anonymous-namespace'::PartialViewProxy &lm::ngram::trie::`anonymous-namespace'::PartialViewProxy::operator =(const util::ValueBlock &)'
E:\1102\vcpkg\buildtrees\kenlm\src\2b1d91de6b-8796a520fb.clean\lm\trie_sort.cc(42): note: or       'lm::ngram::trie::`anonymous-namespace'::PartialViewProxy &lm::ngram::trie::`anonymous-namespace'::PartialViewProxy::operator =(const lm::ngram::trie::`anonymous-namespace'::PartialViewProxy &)'

This issue due to an internal change in compiler. For fixing this issue, we need to change util/proxy_iterator.hh as below:
Line 80:

Proxy operator*() { return p_; }
const Proxy operator*() const { return p_; }

change to:

Proxy operator*() const { return p_; }

I have added a patch to solve this problem temporarily on VCPKG, the related PR microsoft/vcpkg#14382. I submit this issue and want to fix this error on upstream.

[kpu]

Done.