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[BUG] No support for multi-argument indexing #482
Description
Title: No support for multi-argument indexing.
Description:
An expression like x[y,z]
lowers to cpp2::assert_in_bounds(x, y, z),
but has an arity of 2.
Minimal reproducer (https://cpp2.godbolt.org/z/TPoGe1czc):
t: type = {
operator[]: (inout this, x: _, y: _) -> i32 = 42;
}
main: () = {
[[assert: t()[1, 2] == 42]]
}
Commands:
cppfront -clean-cpp1 main.cpp2
clang++17 -std=c++23 -stdlib=libc++ -lc++abi -pedantic-errors -Wall -Wextra -Wconversion -I . main.cppExpected result:
It doesn't seem trivial to support multi-argument indexing in cpp2::assert_in_bounds.
See https://en.cppreference.com/w/cpp/container/mdspan/operator_at.
cpp2::Default.expects(t()[1, 2]==42, "");Actual result and error:
cpp2::Default.expects(cpp2::assert_in_bounds(t(), 1, 2)==42, "");Cpp2 lowered to Cpp1.
#include "cpp2util.h"
class t;
class t {
public: [[nodiscard]] auto operator[](auto const& x, auto const& y) -> cpp2::i32;
public: t() = default;
public: t(t const&) = delete; /* No 'that' constructor, suppress copy */
public: auto operator=(t const&) -> void = delete;
};
auto main() -> int;
[[nodiscard]] auto t::operator[](auto const& x, auto const& y) -> cpp2::i32 { return 42; }
auto main() -> int{
cpp2::Default.expects(cpp2::assert_in_bounds(t(), 1, 2)==42, "");
}Output.
build/_cppfront/main.cpp:20:25: error: no matching function for call to 'assert_in_bounds'
cpp2::Default.expects(cpp2::assert_in_bounds(t(), 1, 2)==42, "");
^~~~~~~~~~~~~~~~~~~~~~
raw.githubusercontent.com/hsutter/cppfront/main/include/cpp2util.h:399:6: note: candidate function template not viable: requires 2 arguments, but 3 were provided
auto assert_in_bounds(auto&& x, auto&& arg CPP2_SOURCE_LOCATION_PARAM_WITH_DEFAULT) -> decltype(auto)
^
raw.githubusercontent.com/hsutter/cppfront/main/include/cpp2util.h:407:6: note: candidate function template not viable: requires 2 arguments, but 3 were provided
auto assert_in_bounds(auto&& x, auto&& arg CPP2_SOURCE_LOCATION_PARAM_WITH_DEFAULT) -> decltype(auto)
^
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