aboutsummaryrefslogtreecommitdiff
path: root/c/common.h
blob: a4f1fd40aa07b0bf3289454a6cf729e9494be451 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
#ifndef COMMON_H
#define COMMON_H

#include <memory>
#include <optional>
#include <windows.h>

#ifdef UNICODE
#define WA "W"
#else
#define WA "A"
#endif

struct Win32Error : public std::exception
{
	Win32Error(DWORD dwErr);
	~Win32Error();
	virtual const char* what() const noexcept override;
	virtual const TCHAR* twhat() const noexcept;
private:
	DWORD m_dwErr;
	char* m_szMsg = NULL;
	wchar_t* m_wszMsg = NULL;
};

struct Library
{
	Library(const TCHAR* tszLibrary);
	~Library();
	template <typename T> T* GetProcAddress(const char* szProc);
private:
	HMODULE m_hModule;
};

template <typename T>
T* Library::GetProcAddress(const char* const szProc)
{
	return (T*)(void*)::GetProcAddress(m_hModule, szProc);
}

/* Create and return an object of type C. If construction fails,
 * return nothing. The returned value must be checked before being
 * used, as dereferencing is undefined if the value is empty. */
template <class C, typename ...T>
std::optional<C> try_make(T ...args)
{
	try {
		return C(args...);
	} catch (...) {
		return {};
	}
}

/* Return integer scaled for current DPI. */
inline int Dpi(const int i)
{
	extern int g_iDPI;
	return MulDiv(i, g_iDPI, 96);
}

inline int Cmp(const int a, const int b)
{
	if (a == b) return 0;
	if (a > b) return 1;
	return -1;
}

#endif