// PR9548 - "no known conversion from 'vector<string>' to 'vector<string>'"
// vector<string> refers to two different types here. Make sure the message
// gives a way to tell them apart.
classversa_string;
typedefversa_stringstring;
namespacestd{template<typenameT>classvector;}
usingstd::vector;
voidf(vector<string>v);
namespacestd{
classbasic_string;
typedefbasic_stringstring;
template<typenameT>classvector{};
voidg(){
vector<string>v;
f(v);
}
}// end namespace std
// CHECK-ELIDE-NOTREE: no matching function for call to 'f'
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'vector<class std::basic_string>' to 'vector<class versa_string>' for 1st argument
// CHECK-NOELIDE-NOTREE: no matching function for call to 'f'
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'vector<class std::basic_string>' to 'vector<class versa_string>' for 1st argument
// CHECK-ELIDE-TREE: no matching function for call to 'f'
// CHECK-NOELIDE-TREE: [class std::basic_string != class versa_string]>
template<int...A>
classI1{};
voidset1(I1<1,2,3,4,2,3,4,3>){};
voidtest1(){
set1(I1<1,2,3,4,2,2,4,3,7>());
}
// CHECK-ELIDE-NOTREE: no matching function for call to 'set1'
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'I1<[5 * ...], 2, [2 * ...], 7>' to 'I1<[5 * ...], 3, [2 * ...], (no argument)>' for 1st argument
// CHECK-NOELIDE-NOTREE: no matching function for call to 'set1'
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'I1<1, 2, 3, 4, 2, 2, 4, 3, 7>' to 'I1<1, 2, 3, 4, 2, 3, 4, 3, (no argument)>' for 1st argument
// CHECK-ELIDE-TREE: no matching function for call to 'set1'
// CHECK-ELIDE-NOTREE: no matching function for call to 'set2'
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'I2<double, [...], int>' to 'I2<int, [...], (default) void>' for 1st argument
// CHECK-NOELIDE-NOTREE: no matching function for call to 'set2'
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'I2<double, int, int>' to 'I2<int, int, (default) void>' for 1st argument
// CHECK-ELIDE-TREE: no matching function for call to 'set2'
// CHECK-ELIDE-NOTREE: no matching function for call to 'set5'
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'Alpha<Beta<Gamma<void, void>, double>, double>' to 'Alpha<Beta<Gamma<Delta<int, int>, int>, int>, int>' for 1st argument
// CHECK-NOELIDE-NOTREE: no matching function for call to 'set5'
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'Alpha<Beta<Gamma<void, void>, double>, double>' to 'Alpha<Beta<Gamma<Delta<int, int>, int>, int>, int>' for 1st argument
// CHECK-ELIDE-TREE: no matching function for call to 'set5'
// CHECK-ELIDE-NOTREE: no matching function for call to 'set5'
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'Alpha<Beta<Delta<int, int>, [...]>, [...]>' to 'Alpha<Beta<Gamma<Delta<int, int>, int>, [...]>, [...]>' for 1st argument
// CHECK-NOELIDE-NOTREE: no matching function for call to 'set5'
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'Alpha<Beta<Delta<int, int>, int>, int>' to 'Alpha<Beta<Gamma<Delta<int, int>, int>, int>, int>' for 1st argument
// CHECK-ELIDE-TREE: no matching function for call to 'set5'
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'S9<[2 * ...], S9<[2 * ...], double>>' to 'S9<[2 * ...], S9<[2 * ...], const double>>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'S9<int, char, S9<int, char, double>>' to 'S9<int, char, S9<int, char, const double>>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'class_types<[...], (no argument)>' to 'class_types<[...], int>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'class_types<[2 * ...], int>' to 'class_types<[2 * ...], (no argument)>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'class_types<int, (no argument)>' to 'class_types<int, int>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'class_types<int, int, int>' to 'class_types<int, int, (no argument)>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'class_ints<0, [...], 6>' to 'class_ints<2, [...], (no argument)>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'class_ints<0, 3, 6>' to 'class_ints<2, 3, (no argument)>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'class_template_templates<template tt2, template (no argument)>' to 'class_template_templates<template tt1, template tt1>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'class_template_templates<[2 * ...], template tt1>' to 'class_template_templates<[2 * ...], template (no argument)>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'class_template_templates<template tt2, template (no argument)>' to 'class_template_templates<template tt1, template tt1>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'class_template_templates<template tt1, template tt1, template tt1>' to 'class_template_templates<template tt1, template tt1, template (no argument)>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'class_ptrs<&c13, (no argument)>' to 'class_ptrs<&a13, &b13>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'class_ptrs<[2 * ...], &d13>' to 'class_ptrs<[2 * ...], (no argument)>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'class_ptrs<&c13, (no argument)>' to 'class_ptrs<&a13, &b13>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'class_ptrs<&a13, &b13, &d13>' to 'class_ptrs<&a13, &b13, (no argument)>' for 1st argument
// CHECK-ELIDE-NOTREE: no matching function for call to 'set16'
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'vector<const vector<const int>>' to 'vector<const vector<int>>' for 1st argument
// CHECK-NOELIDE-NOTREE: no matching function for call to 'set16'
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'vector<const vector<const int>>' to 'vector<const vector<int>>' for 1st argument
// CHECK-ELIDE-TREE: no matching function for call to 'set16'
// CHECK-ELIDE-TREE: candidate function not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: vector<
// CHECK-ELIDE-TREE: const vector<
// CHECK-ELIDE-TREE: [const != (no qualifiers)] int>>
// CHECK-NOELIDE-TREE: no matching function for call to 'set16'
// CHECK-NOELIDE-TREE: candidate function not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: vector<
// CHECK-NOELIDE-TREE: const vector<
// CHECK-NOELIDE-TREE: [const != (no qualifiers)] int>>
voidset17(vector<vector<int>>){}
voidtest17(){
set17(vector<constvector<int>>());
}
// CHECK-ELIDE-NOTREE: no matching function for call to 'set17'
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'vector<const vector<[...]>>' to 'vector<vector<[...]>>' for 1st argument
// CHECK-NOELIDE-NOTREE: no matching function for call to 'set17'
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'vector<const vector<int>>' to 'vector<vector<int>>' for 1st argument
// CHECK-ELIDE-TREE: no matching function for call to 'set17'
// CHECK-ELIDE-TREE: candidate function not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: vector<
// CHECK-ELIDE-TREE: [const != (no qualifiers)] vector<
// CHECK-ELIDE-TREE: [...]>>
// CHECK-NOELIDE-TREE: no matching function for call to 'set17'
// CHECK-NOELIDE-TREE: candidate function not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: vector<
// CHECK-NOELIDE-TREE: [const != (no qualifiers)] vector<
// CHECK-NOELIDE-TREE: int>>
voidset18(vector<constvector<int>>){}
voidtest18(){
set18(vector<vector<int>>());
}
// CHECK-ELIDE-NOTREE: no matching function for call to 'set18'
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'vector<vector<[...]>>' to 'vector<const vector<[...]>>' for 1st argument
// CHECK-NOELIDE-NOTREE: no matching function for call to 'set18'
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'vector<vector<int>>' to 'vector<const vector<int>>' for 1st argument
// CHECK-ELIDE-TREE: no matching function for call to 'set18'
// CHECK-ELIDE-TREE: candidate function not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-NOTREE: no matching function for call to 'set19'
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'vector<const vector<[...]>>' to 'vector<volatile vector<[...]>>' for 1st argument
// CHECK-NOELIDE-NOTREE: no matching function for call to 'set19'
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'vector<const vector<int>>' to 'vector<volatile vector<int>>' for 1st argument
// CHECK-ELIDE-TREE: no matching function for call to 'set19'
// CHECK-ELIDE-TREE: candidate function not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: vector<
// CHECK-ELIDE-TREE: [const != volatile] vector<
// CHECK-ELIDE-TREE: [...]>>
// CHECK-NOELIDE-TREE: no matching function for call to 'set19'
// CHECK-NOELIDE-TREE: candidate function not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-NOTREE: no matching function for call to 'set20'
// CHECK-ELIDE-NOTREE: candidate function not viable: no known conversion from 'vector<const vector<[...]>>' to 'vector<const volatile vector<[...]>>' for 1st argument
// CHECK-NOELIDE-NOTREE: no matching function for call to 'set20'
// CHECK-NOELIDE-NOTREE: candidate function not viable: no known conversion from 'vector<const vector<int>>' to 'vector<const volatile vector<int>>' for 1st argument
// CHECK-ELIDE-TREE: no matching function for call to 'set20'
// CHECK-ELIDE-TREE: candidate function not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-NOTREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from 'Foo1<1>' to 'Foo1<2>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function (the implicit move assignment operator) not viable: no known conversion from 'Foo1<1>' to 'Foo1<2>' for 1st argument
// CHECK-ELIDE-NOTREE: no viable overloaded '='
// CHECK-ELIDE-NOTREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from 'Foo1<2>' to 'Foo1<1>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function (the implicit move assignment operator) not viable: no known conversion from 'Foo1<2>' to 'Foo1<1>' for 1st argument
// CHECK-NOELIDE-NOTREE: no viable overloaded '='
// CHECK-NOELIDE-NOTREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from 'Foo1<1>' to 'Foo1<2>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function (the implicit move assignment operator) not viable: no known conversion from 'Foo1<1>' to 'Foo1<2>' for 1st argument
// CHECK-NOELIDE-NOTREE: no viable overloaded '='
// CHECK-NOELIDE-NOTREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from 'Foo1<2>' to 'Foo1<1>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function (the implicit move assignment operator) not viable: no known conversion from 'Foo1<2>' to 'Foo1<1>' for 1st argument
// CHECK-ELIDE-TREE: no viable overloaded '='
// CHECK-ELIDE-TREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: Foo1<
// CHECK-ELIDE-TREE: [1 != 2]>
// CHECK-ELIDE-TREE: candidate function (the implicit move assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: Foo1<
// CHECK-ELIDE-TREE: [1 != 2]>
// CHECK-ELIDE-TREE: no viable overloaded '='
// CHECK-ELIDE-TREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: Foo1<
// CHECK-ELIDE-TREE: [2 != 1]>
// CHECK-ELIDE-TREE: candidate function (the implicit move assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: Foo1<
// CHECK-ELIDE-TREE: [2 != 1]>
// CHECK-NOELIDE-TREE: no viable overloaded '='
// CHECK-NOELIDE-TREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: Foo1<
// CHECK-NOELIDE-TREE: [1 != 2]>
// CHECK-NOELIDE-TREE: candidate function (the implicit move assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: Foo1<
// CHECK-NOELIDE-TREE: [1 != 2]>
// CHECK-NOELIDE-TREE: no viable overloaded '='
// CHECK-NOELIDE-TREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: Foo1<
// CHECK-NOELIDE-TREE: [2 != 1]>
// CHECK-NOELIDE-TREE: candidate function (the implicit move assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: Foo1<
// CHECK-NOELIDE-TREE: [2 != 1]>
voidPlay2(){
Foo2<1>F1;
Foo2<>F2,F3;
F2=F1;
F1=F2;
F2=F3;
F3=F2;
}
// CHECK-ELIDE-NOTREE: no viable overloaded '='
// CHECK-ELIDE-NOTREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from 'Foo2<1>' to 'Foo2<2>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function (the implicit move assignment operator) not viable: no known conversion from 'Foo2<1>' to 'Foo2<2>' for 1st argument
// CHECK-ELIDE-NOTREE: no viable overloaded '='
// CHECK-ELIDE-NOTREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from 'Foo2<(default) 2>' to 'Foo2<1>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function (the implicit move assignment operator) not viable: no known conversion from 'Foo2<(default) 2>' to 'Foo2<1>' for 1st argument
// CHECK-NOELIDE-NOTREE: no viable overloaded '='
// CHECK-NOELIDE-NOTREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from 'Foo2<1>' to 'Foo2<2>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function (the implicit move assignment operator) not viable: no known conversion from 'Foo2<1>' to 'Foo2<2>' for 1st argument
// CHECK-NOELIDE-NOTREE: no viable overloaded '='
// CHECK-NOELIDE-NOTREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from 'Foo2<(default) 2>' to 'Foo2<1>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function (the implicit move assignment operator) not viable: no known conversion from 'Foo2<(default) 2>' to 'Foo2<1>' for 1st argument
// CHECK-ELIDE-TREE: no viable overloaded '='
// CHECK-ELIDE-TREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: Foo2<
// CHECK-ELIDE-TREE: [1 != 2]>
// CHECK-ELIDE-TREE: candidate function (the implicit move assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: Foo2<
// CHECK-ELIDE-TREE: [1 != 2]>
// CHECK-ELIDE-TREE: no viable overloaded '='
// CHECK-ELIDE-TREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: Foo2<
// CHECK-ELIDE-TREE: [(default) 2 != 1]>
// CHECK-ELIDE-TREE: candidate function (the implicit move assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: Foo2<
// CHECK-ELIDE-TREE: [(default) 2 != 1]>
// CHECK-NOELIDE-TREE: no viable overloaded '='
// CHECK-NOELIDE-TREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: Foo2<
// CHECK-NOELIDE-TREE: [1 != 2]>
// CHECK-NOELIDE-TREE: candidate function (the implicit move assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: Foo2<
// CHECK-NOELIDE-TREE: [1 != 2]>
// CHECK-NOELIDE-TREE: no viable overloaded '='
// CHECK-NOELIDE-TREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: Foo2<
// CHECK-NOELIDE-TREE: [(default) 2 != 1]>
// CHECK-NOELIDE-TREE: candidate function (the implicit move assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: Foo2<
// CHECK-NOELIDE-TREE: [(default) 2 != 1]>
voidPlay3(){
Foo3<1>F1;
Foo3<2,1>F2,F3;
F2=F1;
F1=F2;
F2=F3;
F3=F2;
}
// CHECK-ELIDE-NOTREE: no viable overloaded '='
// CHECK-ELIDE-NOTREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from 'Foo3<1, (no argument)>' to 'Foo3<2, 1>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function (the implicit move assignment operator) not viable: no known conversion from 'Foo3<1, (no argument)>' to 'Foo3<2, 1>' for 1st argument
// CHECK-ELIDE-NOTREE: no viable overloaded '='
// CHECK-ELIDE-NOTREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from 'Foo3<2, 1>' to 'Foo3<1, (no argument)>' for 1st argument
// CHECK-ELIDE-NOTREE: candidate function (the implicit move assignment operator) not viable: no known conversion from 'Foo3<2, 1>' to 'Foo3<1, (no argument)>' for 1st argument
// CHECK-NOELIDE-NOTREE: no viable overloaded '='
// CHECK-NOELIDE-NOTREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from 'Foo3<1, (no argument)>' to 'Foo3<2, 1>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function (the implicit move assignment operator) not viable: no known conversion from 'Foo3<1, (no argument)>' to 'Foo3<2, 1>' for 1st argument
// CHECK-NOELIDE-NOTREE: no viable overloaded '='
// CHECK-NOELIDE-NOTREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from 'Foo3<2, 1>' to 'Foo3<1, (no argument)>' for 1st argument
// CHECK-NOELIDE-NOTREE: candidate function (the implicit move assignment operator) not viable: no known conversion from 'Foo3<2, 1>' to 'Foo3<1, (no argument)>' for 1st argument
// CHECK-ELIDE-TREE: no viable overloaded '='
// CHECK-ELIDE-TREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: Foo3<
// CHECK-ELIDE-TREE: [1 != 2],
// CHECK-ELIDE-TREE: [(no argument) != 1]>
// CHECK-ELIDE-TREE: candidate function (the implicit move assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: Foo3<
// CHECK-ELIDE-TREE: [1 != 2],
// CHECK-ELIDE-TREE: [(no argument) != 1]>
// CHECK-ELIDE-TREE: no viable overloaded '='
// CHECK-ELIDE-TREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: Foo3<
// CHECK-ELIDE-TREE: [2 != 1],
// CHECK-ELIDE-TREE: [1 != (no argument)]>
// CHECK-ELIDE-TREE: candidate function (the implicit move assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-ELIDE-TREE: Foo3<
// CHECK-ELIDE-TREE: [2 != 1],
// CHECK-ELIDE-TREE: [1 != (no argument)]>
// CHECK-NOELIDE-TREE: no viable overloaded '='
// CHECK-NOELIDE-TREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: Foo3<
// CHECK-NOELIDE-TREE: [1 != 2],
// CHECK-NOELIDE-TREE: [(no argument) != 1]>
// CHECK-NOELIDE-TREE: candidate function (the implicit move assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: Foo3<
// CHECK-NOELIDE-TREE: [1 != 2],
// CHECK-NOELIDE-TREE: [(no argument) != 1]>
// CHECK-NOELIDE-TREE: no viable overloaded '='
// CHECK-NOELIDE-TREE: candidate function (the implicit copy assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument
// CHECK-NOELIDE-TREE: Foo3<
// CHECK-NOELIDE-TREE: [2 != 1],
// CHECK-NOELIDE-TREE: [1 != (no argument)]>
// CHECK-NOELIDE-TREE: candidate function (the implicit move assignment operator) not viable: no known conversion from argument type to parameter type for 1st argument