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[Bug c++/61178] New: expansion pattern '#'nontype_argument_pack' not supported by dump_expr#


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61178

            Bug ID: 61178
           Summary: expansion pattern '#'nontype_argument_pack' not
                    supported by dump_expr#
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tower120 at gmail dot com

I got strange error:

expansion pattern '#'nontype_argument_pack' not supported by dump_expr#

With the following code:
http://coliru.stacked-crooked.com/a/bbacd7e9bec149f0

------------------------------------------------------------------------------
#include <iostream>
#include <utility>
#include <type_traits>
#include <typeinfo>

using namespace std;


struct Void{
    static constexpr int size = 0;
};

template<typename T0, typename T1>
class Variadic{
private:
    typedef Variadic<T0, T1> thisT;

public:
    /** Do not use this constructor */
    Variadic(T0 el0, T1 el1): value(el0), next(el1) {}

    // avoiding decltype
    typedef T0 valueT;
    T0 value;

    typedef T1 nextT;
    T1 next; // may be next pair

    /**
     * Chainable method
     */
    template<typename ValueT>
    /*constexpr*/ inline Variadic<ValueT, thisT> add(ValueT value){
        return Variadic<ValueT, thisT>(value, (*this) );
    }

};

template<typename T>
static inline Variadic<T, Void> make_variadic(T value){
    return Variadic<T, Void>(value, Void());
}




/// ERROR IS HERE!
template<typename Arg0, typename... Args>
static inline auto make_variadic(Arg0 value0, Args... values) -> decltype(
fill(make_variadic<Arg0>(value0), values...) ) {
    return fill(make_variadic<Arg0>(value0), values...);
}


///  THIS ONE BELOW, WORKS FINE
/*
template<typename Arg0, typename... Args>
static inline auto make_variadic(Arg0 value0, Args... values) ->
decltype(fill(Variadic<Arg0, Void>(value0, Void()), values...)) {
    return fill(Variadic<Arg0, Void>(value0, Void()), values...);
}*/


template<typename T, typename Arg0, typename... Args>
static inline auto fill(T self, Arg0 value, Args... values) ->
decltype(fill(self.add(value), values...)){
    return fill(self.add(value), values...);
}

template<typename T, typename Arg0>
static inline auto fill(T self, Arg0 value) -> decltype(self.add(value)){
    return self.add(value);
}



int main()
{
    auto list = make_variadic(1, 2, 3);
}


------------------------------------------------------------------------------
Command line from coliru:
g++-4.8 -std=c++11  -O2 -Wall -Wextra -pedantic -pthread -pedantic-errors
main.cpp -lm  && ./a.out


Clang compile this without errors.


If I replace make_variadic call (see code above) with function body, it works
ok.


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