GetExeModulePath.hpp

#ifndef GETEXEMODULEPATH__HPP__
#define GETEXEMODULEPATH__HPP__

#if !defined(_WINDOWS_) && !defined(__AFX_H__)
#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#endif

#include <string>

inline std::wstring GetModuleFullPathImpl(HMODULE moduleHandle, wchar_t module[], bool directoryOnly) {
	std::wstring moduleName;
	for (int bufferLength = MAX_PATH; bufferLength < (1 << 15) + MAX_PATH;) {
		moduleName.resize(bufferLength);
		::SetLastError(0);
		const auto r = ::GetModuleFileNameW(
			moduleHandle, &moduleName[0], bufferLength);
		if (ERROR_INSUFFICIENT_BUFFER == ::GetLastError()) {
			bufferLength += 256;
		}
		else {
			moduleName.resize(r);
			break;
		}
	}

	const auto required =
		::GetFullPathNameW(moduleName.c_str(), 0, nullptr, nullptr);
	if (required == 0) {
		return{};
	}

	std::wstring result;
	result.resize(required + 1);
	wchar_t* filePart = nullptr;
	auto n = ::GetFullPathNameW(
		moduleName.c_str(), required, &result[0], &filePart);
	if (n > 0 && filePart && directoryOnly) {
		*filePart = '\0';
		result.resize(filePart - &result[0]);
	}
	else {
		result.resize(n);
	}
	return result;
}

inline std::wstring GetExeModuleDirectory()
{
	return GetModuleFullPathImpl(nullptr, true);
}

inline std::wstring GetExeModulePath()
{
	return GetModuleFullPathImpl(nullptr, false);
}

#endif // #ifndef GETEXEMODULEPATH__HPP__