[THRIFT-5465] TEnumIterator lacks equality operator and fails when used in gcc debug containers.

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: C++ - Library

Environment

Compiler: (GCC) 11.1.0

OS: Arch Linux

Language

C++

• Assignee: Unassigned
• Reporter: Joshua L
• Created: 28/Sep/21 19:03
• Updated: 28/Sep/21 19:03

Description

When compiling Apache arrow parquet like so:

cmake ../ -DCMAKE_BUILD_TYPE=DEBUG -DARROW_CXXFLAGS="-D_GLIBCXX_DEBUG" -DARROW_PARQUET=1 

The following error occurs in thrift compiler generated code:

/usr/include/c++/11.1.0/debug/map.h:151:5:   required from ‘std::__debug::map<_Key, _Tp, _Cmp, _Allocator>::map(_InputIterator, _InputIterator, const _Compare&, const _Allocator&) [with _InputIterator = apache::thrift::TEnumIterator; _Key = int; _Tp = co
nst char*; _Compare = std::less<int>; _Allocator = std::allocator<std::pair<const int, const char*> >]’                        
/home/snapcore/arrow/cpp/src/generated/parquet_types.cpp:36:166:   required from here                                                                                                                                                                         
/usr/include/c++/11.1.0/debug/helper_functions.h:174:22: error: no match for ‘operator==’ (operand types are ‘apache::thrift::TEnumIterator’ and ‘apache::thrift::TEnumIterator’)                                                                             
  174 |       return __first == __last                                                

This is because the type TEnumIterator is being stored in a stl debug map:

const std::map<int, const char*> _Type_VALUES_TO_NAMES(::apache::thrift::TEnumIterator(8, _kTypeValues, _kTypeNames), ::apache::thrift::TEnumIterator(-1, NULL, NULL));

that does an equality comparison on types stored for validity, but TEnumIterator lacks a comparison operator on non-windows platforms it seems:

A very simple solution here is to add to Thrift.h:

#include <thrift/windows/Operators.h>

which includes a dummy comparison operator I believe. Probably not ideal, but that is the current workaround I found.