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

smallvec_type.hpp defines SmallVector container 

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





1     COMMENT (*)
2     BLANK (-)
3     *
4     *
5     *
6     *
7     *
8     *
9     -
10    *
11    -
12    Header guard
13    Header guard
14    -
15    Include the OpenTTD type-safe memory allocation functions
16    Include the OpenTTD type-safe memory access functions
17    -
18    *
19    *
20    *
21    *
22    *
23    *
24    *
25    *
26    *
27    *
28    Sets up a class template with two paramters: a type and a base size
29    BLOCK START - SmallVector, STL-like vector container
30    Begin protected section
31    Pointer to the container data
32    Declare the number of items in the container
33    The total number of items storable in the vector
34    *
35    Begins the public section
36    Defines the defaul constructor with a null-value initialization list
37    *
38    *
39    *
40    *
41    *
42    Declares a copy constructor with an null value initialization list
43    BLOCK START - SmallVector copy constructor
44    Return the assigned vector
45    BLOCK END - SmallVector copy constructor
46    -
47    *
48    *
49    *
50    *
51    Sets up a function template with an input base size
52    Defines a copy constructor with a null initialization list
53    BLOCK START - SmallVector copy constructor
54    Assign the input vector to the current vector. Return the new assignment
55    BLOCK END - SmallVector
56    -
57    *
58    *
59    *
60    *
61    Defines the overloaded assignment operator with an input SmallVector
62    BLOCK START - Overloaded = operator for SmallVector
63    Assigns the input SmallVector's elements to the current SmallVector
64    Returns a pointer to the current SmallVector
65    BLOCK END - Overloaded = operator for SmallVector
66    -
67    *
68    *
69    *
70    *
71    Sets up a function template with an input base size
72    Defines the overloaded assignment operator with an input SmallVector
73    BLOCK START - Overloaded = operator for SmallVector
74    Assigns the input SmallVector's elements to the current SmallVector
75    Returns a pointer to the current SmallVector
76    BLOCK END - Overloaded = operator for SmallVector
77    -
78    Defines a destructor for SmallVector
79    BLOCK START - SmallVector destructor
80    Destroys the allocated data
81    BLOCK END - SmallVector destructor
82    -
83    *
84    *
85    *
86    Sets up a function template with an input base size
87    Defines SmallVector::Assign with one input argument: The SmallVector to
      assign
88    BLOCK START - SmallVector::Assign, assigns another SmallVector
89    If the SmallVector to assign is already this object, do nothing
90    -
91    Clear the current object
92    If object to assign has data, copy the data to this SmallVector
93    BLOCK END - SmallVector::Assign
94    -
95    *
96    *
97    *
98    Defines SmallVector::Clear with no arguments
99    BLOCK START - SmallVector::Clear, simple vector reset
100   *
101   *
102   *
103   Clear the item counter
104   BLOCK END - SmallVector::Clear
105   -
106   *
107   *
108   *
109   Defines SmallVector::Reset with no arguments
110   BLOCK START - SmallVector::Reset, empties the vector
111   Clear the item counter
112   Clear the vector capacity counter
113   Destroy all data
114   Invalidate the data pointer
115   BLOCK END - SmallVector::Reset
116   -
117   *
118   *
119   *
120   Defines SmallVector::Compact with no arguments
121   BLOCK START - SmallVector::Compact, shrinks the vector if possible
122   Calculates the capacity required by the vector
123   If the computed capacity is the same or larger, nothing to do
124   -
125   Updates the capacity with the computed value
126   Reallocates the SmallVector with the computed capacity
127   BLOCK END - SmallVector::Compact
128   -
129   *
130   *
131   *
132   *
133   *
134   Defines SmallVector::Append with one argument, the item count to append
135   BLOCK START - SmallVector::Append, adds an item to the end
136   Store the current number of items
137   Add the count of items to add to the tracking variable
138   -
139   If the new size is larger than the current capacity...
140   Ensure that the capacity matches the desired base size
141   Reallocate memory to grow the array
142   End check for the need to grow
143   -
144   Return a pointer to the start of the new data
145   BLOCK END - SmallVector::Append
146   -
147   *
148   *
149   *
150   *
151   Defines SmallVector::Resize with one argument, the number of desired items
      in the vector
152   BLOCK START - SmallVector::Resize, changes the vector size
153   Updating the count of items
154   -
155   If the new size is larger than the current capacity...
156   Ensure that the capacity matches the desired base size
157   Reallocate memory to grow the array
158   End check for the need to grow
159   BLOCK END - SmallVector::Resize
160   -
161   *
162   *
163   *
164   *
165   *
166   *
167   Defines SmallVector::Find with one argument, a pointer to the item to
      find (as const pointer)
168   BLOCK START - SmallVector::Find, finds an item
169   Get the item at the beginning of the SmallVector
170   Get the item at the end of the SmallVector
171   Increment through the vector until the item matches input or we're at
      the end
172   Return the discovered item (item or End)
173   BLOCK END - SmallVector::Find
174   -
175   *
176   *
177   *
178   *
179   *
180   *
181   Defines SmallVector::Clear with one argument, a pointer to the item to
      find (as a const pointer)
182   BLOCK START - SmallVector::Find, finds an item
183   Get the item at the beginning of the SmallVector
184   Get the item at the end of the SmallVector
185   Increment through the vector until the item matches input or we're at
      the end
186   Return the discovered item (item or End)
187   BLOCK END - SmallVector::Find
188   -
189   *
190   *
191   *
192   *
193   *
194   *
195   Defines SmallVector::FindIndex with one argument, a pointer to the item
      to find
196   BLOCK START - SmallVector::FindIndex, gets an item's vector position
197   Initializes an index counter to 0
198   Get the item at the beginning of the SmallVector
199   Get the item at the end of the SmallVector
200   Loop through all items while the desired item hasn't been found
201   Increment to the next item
202   Increment the index counter
203   Repeat loop as needed
204   If we didn't find the item, return -1 (fail), otherwise return the index
      counter
205   BLOCK END - SmallVector::FindIndex
206   -
207   *
208   *
209   *
210   *
211   *
212   *
213   Defines SmallVector::Clear with one argument: a pointer to the item to
      verify
214   BLOCK START - SmallVector::Contains, checks for an item
215   Return the boolean result of an attempted Find
216   BLOCK END - SmallVector::Contains
217   -
218   *
219   *
220   *
221   *
222   *
223   Defines SmallVector::Erase with one argument, a pointer to the item to
      remove
224   BLOCK START - SmallVector::Erase, removes items
225   Checks that the input item is within the bounds of the SmallVector
226   Replaces the item with the last item in the SmallVector
227   BLOCK END - SmallVector::Erase
228   -
229   *
230   *
231   *
232   *
233   *
234   Defines SmallVector::Clear with two arguments, the item position to start,
      and the item count to remove
235   BLOCK START - SmallVector::ErasePreservingOrder, removes items and replaces
      from the back
236   If no items are requested for erasure, there's no work to do
237   Verify that the start position is valid
238   Verify that the final position is valid
239   Remove the number of requested items from the counter
240   Find the number of items to move from the back
241   Overwrite deleted items from the back of the SmallVector
242   BLOCK END - SmallVector::ErasePreservingOrder
243   -
244   *
245   *
246   *
247   *
248   *
249   *
250   Defines SmallVector::Include with one argument: a pointer to the item
      to test and append
251   BLOCK START - SmallVector::Include, tests an adds item to vector
252   Check if the SmallVector already contains the input item
253   If it does not, append it to the end
254   Return the boolean result if the item was already present
255   BLOCK END - SmallVector::Include
256   -
257   *
258   *
259   *
260   *
261   *
262   Defines SmallVector::Length with no arguments
263   BLOCK START - SmallVector::Length, finds the vector item length
264   Returns the number of items
265   BLOCK END - SmallVector::Length
266   -
267   *
268   *
269   *
270   *
271   *
272   Defines SmallVector::Begin with no arguments
273   BLOCK START - SmallVector::Begin, finds the first item
274   Returns a constant pointer to the start of the item data
275   BLOCK END - SmallVector::Begin
276   -
277   *
278   *
279   *
280   *
281   *
282   Defines SmallVector::Begin with no arguments
283   BLOCK START - SmallVector::Begin, finds the first item
284   Returns a pointer to the start of the item data
285   BLOCK END - SmallVector::Begin
286   -
287   *
288   *
289   *
290   *
291   *
292   Defines SmallVector::End with no arguments
293   BLOCK START - SmallVector::End, finds the last item
294   Returns a constant pointer to the last item in the SmallVector
295   BLOCK END - SmallVector::End
296   -
297   *
298   *
299   *
300   *
301   *
302   Defines SmallVector::End with no arguments
303   BLOCK START - SmallVector::End, finds the last item
304   Returns a pointer to the last item in the SmallVector
305   BLOCK END - SmallVector::End
306   -
307   *
308   *
309   *
310   *
311   *
312   *
313   Defines SmallVector::Get with one argument: the position to return
314   BLOCK START - SmallVector::Get, returns a constant pointer to an item
315   *
316   Verifies that the index exists
317   Returns a constant pointer to the item at the position
318   BLOCK END - SmallVector::Get
319   -
320   *
321   *
322   *
323   *
324   *
325   *
326   Defines SmallVector::Get with one argument: the position to return
327   BLOCK START - SmallVector::Get, returns a pointer to an item
328   *
329   Verifies that the index exists
330   Returns a pointer to the item at the position
331   BLOCK END - SmallVector::Get
332   -
333   *
334   *
335   *
336   *
337   *
338   *
339   Defines the overloaded array access operator with an input SmallVector
340   BLOCK START - SmallVector [] operator overload
341   Verify that the input index is valid
342   Return the item at the index
343   BLOCK END - SmallVector [] operator overload
344   -
345   *
346   *
347   *
348   *
349   *
350   *
351   Defines the overloaded array access operator with an input SmallVector
352   BLOCK START - SmallVector [] operator overload
353   Verify that the input index is valid
354   Return the item at the index
355   BLOCK END - SmallVector [] operator overload
356   BLOCK END - SmallVector
357   -
358   -
359   *
360   *
361   *
362   *
363   *
364   *
365   *
366   *
367   *
368   *
369   Sets up a class template with two parameters: a type and base size
370   Defines AutoFreeSmallVector as an extended SmallVector
371   Begin the public section of AutoFreeSmallVector
372   Define the AutoFreeSmallVector destructor
373   BLOCK START - AutoFreeSmallVector destructor
374   Remove all items in the vector
375   BLOCK END - AutoFreeSmallVector destructor
376   -
377   *
378   *
379   *
380   Defines AutoFreeSmallVector::Clear with no arguments
381   BLOCK START - AutoFreeSmallVector::Clear
382   Loop through all members of the vector
383   Destroy the data at the index
384   Repeat loop until all data is freed
385   -
386   Set vector size to zero
387   BLOCK END - AutoFreeSmallVector::Clear
388   BLOCK END - AutoFreeSmallVector
389   -
390   *
391   *
392   *
393   *
394   *
395   *
396   *
397   *
398   *
399   *
400   Sets up a class template with two parameters: a type and base size
401   Defines AutoDeleteSmallVector as an extended SmallVector
402   Begins the public section of AutoDeleteSmallVector
403   Defines the AutoDeleteSmallVector destructor
404   BLOCK START - AutoDeleteSmallVector destructor
405   Remove all items in the vector
406   BLOCK END - AutoDeleteSmallVector destructor
407   -
408   *
409   *
410   *
411   Defines AutoDeleteSmallVector::Clear with no arguments
412   BLOCK START - AutoDeleteSmallVector::Clear, deletes all items
413   Loop through items in the SmallVector
414   Destory the item
415   Repeat loop as needed
416   -
417   Clear the item counter
418   BLOCK END - AutoDeleteSmallVector::Clear
419   BLOCK END - AutoDeleteSmallVector
420   -
421   Adds a typedef for a string list from an AutoFreeSmallVector
422   *
423   Header guard end