BLI: generally improve C++ data structures

The main focus here was to improve the docs significantly. Furthermore,
I reimplemented `Set`, `Map` and `VectorSet`. They are now (usually)
faster, simpler and more customizable. I also rewrote `Stack` to make
it more efficient by avoiding unnecessary copies.

Thanks to everyone who helped with constructive feedback.

Approved by brecht and sybren.

Differential Revision: https://developer.blender.org/D7931

1 files changed, 25 insertions, 2 deletions

diff --git a/tests/gtests/blenlib/BLI_array_test.cc b/tests/gtests/blenlib/BLI_array_test.cc
index b1aa24aa808..66f69f5c309 100644
--- a/tests/gtests/blenlib/BLI_array_test.cc
+++ b/tests/gtests/blenlib/BLI_array_test.cc
@@ -1,4 +1,5 @@
 #include "BLI_array.hh"
+#include "BLI_strict_flags.h"
 #include "testing/testing.h"
 
 using namespace BLI;
@@ -7,12 +8,14 @@ TEST(array, DefaultConstructor)
 {
   Array<int> array;
   EXPECT_EQ(array.size(), 0);
+  EXPECT_TRUE(array.is_empty());
 }
 
 TEST(array, SizeConstructor)
 {
   Array<int> array(5);
   EXPECT_EQ(array.size(), 5);
+  EXPECT_FALSE(array.is_empty());
 }
 
 TEST(array, FillConstructor)
@@ -55,7 +58,7 @@ TEST(array, CopyConstructor)
 
   EXPECT_EQ(array.size(), 4);
   EXPECT_EQ(new_array.size(), 4);
-  EXPECT_NE(array.begin(), new_array.begin());
+  EXPECT_NE(array.data(), new_array.data());
   EXPECT_EQ(new_array[0], 5);
   EXPECT_EQ(new_array[1], 6);
   EXPECT_EQ(new_array[2], 7);
@@ -83,7 +86,7 @@ TEST(array, CopyAssignment)
   new_array = array;
   EXPECT_EQ(new_array.size(), 3);
   EXPECT_EQ(array.size(), 3);
-  EXPECT_NE(array.begin(), new_array.begin());
+  EXPECT_NE(array.data(), new_array.data());
   EXPECT_EQ(new_array[0], 1);
   EXPECT_EQ(new_array[1], 2);
   EXPECT_EQ(new_array[2], 3);
@@ -101,3 +104,23 @@ TEST(array, MoveAssignment)
   EXPECT_EQ(new_array[1], 2);
   EXPECT_EQ(new_array[2], 3);
 }
+
+/**
+ * Tests that the trivially constructible types are not zero-initialized. We do not want that for
+ * performance reasons.
+ */
+TEST(array, TrivialTypeSizeConstructor)
+{
+  Array<char, 1> *array = new Array<char, 1>(1);
+  char *ptr = &(*array)[0];
+  array->~Array();
+
+  const char magic = 42;
+  *ptr = magic;
+  EXPECT_EQ(*ptr, magic);
+
+  new (array) Array<char, 1>(1);
+  EXPECT_EQ((*array)[0], magic);
+  EXPECT_EQ(*ptr, magic);
+  delete array;
+}