Changeset - r28635:e3d8752cbdad
[Not reviewed]
master
0 2 1
Jonathan G Rennison - 10 months ago 2024-01-27 17:17:27
j.g.rennison@gmail.com
Codechange: Simplify SetBitIterator

Use FindFirstBit and KillFirstBit, allowing simpler iterator equality
Add simple test
3 files changed with 40 insertions and 4 deletions:
0 comments (0 inline, 0 general)
src/core/bitmath_func.hpp
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@@ -294,7 +294,7 @@ struct SetBitIterator {
 

	
 
		bool operator==(const Iterator &other) const
 
		{
 
			return this->bitset == other.bitset && (this->bitset == 0 || this->bitpos == other.bitpos);
 
			return this->bitset == other.bitset;
 
		}
 
		bool operator!=(const Iterator &other) const { return !(*this == other); }
 
		Tbitpos operator*() const { return this->bitpos; }
 
@@ -305,12 +305,14 @@ struct SetBitIterator {
 
		Tbitpos bitpos;
 
		void Validate()
 
		{
 
			while (this->bitset != 0 && (this->bitset & 1) == 0) this->Next();
 
			if (this->bitset != 0) {
 
				typename std::make_unsigned<Tbitset>::type unsigned_value = this->bitset;
 
				this->bitpos = static_cast<Tbitpos>(FindFirstBit(unsigned_value));
 
			}
 
		}
 
		void Next()
 
		{
 
			this->bitset = static_cast<Tbitset>(this->bitset >> 1);
 
			this->bitpos++;
 
			this->bitset = KillFirstBit(this->bitset);
 
		}
 
	};
 

	
src/tests/CMakeLists.txt
Show inline comments
 
add_test_files(
 
    bitmath_func.cpp
 
    landscape_partial_pixel_z.cpp
 
    math_func.cpp
 
    mock_environment.h
src/tests/bitmath_func.cpp
Show inline comments
 
new file 100644
 
/*
 
 * This file is part of OpenTTD.
 
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 
 */
 

	
 
/** @file bitmath_func.cpp Test functionality from core/bitmath_func. */
 

	
 
#include "../stdafx.h"
 

	
 
#include "../3rdparty/catch2/catch.hpp"
 

	
 
#include "../core/bitmath_func.hpp"
 

	
 
TEST_CASE("SetBitIterator tests")
 
{
 
	auto test_case = [&](auto input, std::initializer_list<uint> expected) {
 
		auto iter = expected.begin();
 
		for (auto bit : SetBitIterator(input)) {
 
			if (iter == expected.end()) return false;
 
			if (bit != *iter) return false;
 
			++iter;
 
		}
 
		return iter == expected.end();
 
	};
 
	CHECK(test_case(0, {}));
 
	CHECK(test_case(1, { 0 }));
 
	CHECK(test_case(42, { 1, 3, 5 }));
 
	CHECK(test_case(0x8080FFFFU, { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 23, 31 }));
 
	CHECK(test_case(INT32_MIN, { 31 }));
 
	CHECK(test_case(INT64_MIN, { 63 }));
 
}
0 comments (0 inline, 0 general)