* In some cases, clang might try to cast an ondemand::document to an
ondemand::document, instead of calling the move constructor. So we
can disable the template cast.
* In some cases, clang might get confused when constructing an ondemand
document in a constructor: instead of calling the move constructor, it
somehow ends up trying to cast a document to a document. We can easily
disallow this behavior with std::enable_if.
* making compatible with C++11
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Co-authored-by: Daniel Lemire <dlemire@lemire.me>
Daniel Lemire
a33fdc2770