[Boost Error] gcc.compile.c++ libs/python/src/converter/builtin_converters.cpp:51:35: error: invalid conversion from ‘const void’ to ‘void*’ [-fpermissive] return PyUnicode_Check(obj) ? _PyUnicode_AsString(obj) : 0;

[Goal]

• Boost를 python 버전과 함께 install 할 때 발생하는 문제를 해결할 수 있다.

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[Reference Site]

[ https://stackoverflow.com/questions/54991157/cant-compile-boost-python-1-65-1-with-msvc2015 ]
[ https://github.com/boostorg/python/commit/660487c43fde76f3e64f1cb2e644500da92fe582#diff-467cabb22a6c637452d730accca26d2e ]

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[Cause]

• Boost python 라이브러리를 설치할 때, python version에 따른 경로를 찾지 못하여 문제가 발생하였기 때문에 boost package를 일부 수정

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[Process]

• [Step 1] boost package 내부 코드인 `~/boost_1_XX_X/libs/python/src/converter/builtin_converters.cpp`를 수정 (Line 38 ~ 47)
  • Before

// An lvalue conversion function which extracts a char const* from a
// Python String.
#if PY_VERSION_HEX < 0x03000000
void* convert_to_cstring(PyObject* obj)
{
  return PyString_Check(obj) ? PyString_AsString(obj) : 0;
}
#else
void* convert_to_cstring(PyObject* obj)
{
  return PyUnicode_Check(obj) ? _PyUnicode_AsString(obj) : 0;
}

 

• •  After

// An lvalue conversion function which extracts a char const* from a
// Python String.
#if PY_VERSION_HEX < 0x03000000
void* convert_to_cstring(PyObject* obj)
{
  return PyString_Check(obj) ? PyString_AsString(obj) : 0;
}
#elif PY_VERSION_HEX < 0x03070000
void* convert_to_cstring(PyObject* obj)
{
  return PyUnicode_Check(obj) ? _PyUnicode_AsString(obj) : 0;
}
#else
void* convert_to_cstring(PyObject* obj)
{
  return PyUnicode_Check(obj) ? const_cast<void*>(reinterpret_cast<const void*>(_PyUnicode_AsString(obj))) : 0;
}
#endif