Decoded: OpenTTD (2003) v1.8 (2018)
Source file: mem_func.hpp
Line-by-line code walkthrough by MaiZure

mem_func.hpp defines type-safe memory movement functions

Original code:
https://github.com/MaiZure/OpenTTD-1.8/blob/master/src/core/mem_func.hpp





1     COMMENT (*)
2     BLANK (-)
3     *
4     *
5     *
6     *
7     *
8     *
9     -
10    *
11    -
12    Header guard
13    Header guard
14    -
15    Includes the OpenTTD math function header
16    -
17    *
18    *
19    *
20    *
21    *
22    *
23    *
24    Sets up a function template with one type parameter
25    Defines MemCpyT with three arguments: a destination memory address, a
      source memory address, and a element count
26    BLOCK START - MemCpyT, generates type-safe memcpy functions
27    Calls memcpy with the passed arguments after converting elements to bytes
28    BLOCK END - MemCpyT
29    -
30    *
31    *
32    *
33    *
34    *
35    *
36    *
37    Sets up a function template with one type parameter
38    Defines MemMoveT with three arguments: destination, source, and element
      count
39    BLOCK START - MemMoveT, generates type-safe memmove functions
40    Calls memmove passing the input arguments and converting elements to bytes
41    BLOCK END - MemMoveT
42    -
43    *
44    *
45    *
46    *
47    *
48    *
49    *
50    Sets up a function template with one type parameter
51    Defines MemSetT with three arguments: a destination, a value, and an element
      count
52    BLOCK START - MemSetT, generates type-safe memset functions
53    Calls memset with the passed arguments after converting elements to bytes
54    BLOCK END - MemSetT 
55    -
56    *
57    *
58    *
59    *
60    *
61    *
62    *
63    *
64    Sets up a function template with one type parameter
65    Defines MemCmpT with three arguments: memory buffer 1, memory buffer 2,
      and an element count
66    BLOCK START - MemCmpT, generates type-safe functions for memcmp
67    Calls memcmp with the passed arguments after converting elements to bytes
68    BLOCK END - MemCmpT
69    -
70    *
71    *
72    *
73    *
74    *
75    *
76    *
77    *
78    Sets up a function template with one type parameter
79    Defines MemReverseT with two arguments: starting and ending pointers
80    BLOCK START - MemReverseT, reverses a section of memory one object at
      a type
81    Checks that both pointers aren't NULL
82    Checks that the first pointer is earlier than the second
83    -
84    Being loop to swap all elements
85    Swap the values of the objects under both pointers
86    Increment the first, decrement the second, (size of T) and continue loop
      if they haven't crossed
87    BLOCK END - MemReverseT
88    -
89    *
90    *
91    *
92    *
93    *
94    *
95    Sets up a function template with one type parameter
96    Defines MemReverseT with two arguments, a pointer and an element count
97    BLOCK START - MemReverseT, reverses a section of memory one object at
      a type -- now based on element count
98    Checks that the pointer isn't NULL
99    -
100   Passes arguments to the MemReverseT with the two pointer signature
101   BLOCK END - MemReverseT
102   -
103   Header guard end