update: cpp style optimization of all cases

src/core/all_cases/all_cases.cc

@@ -1,8 +1,8 @@
 #include <future>
+
 #include "all_cases.h"
 
-namespace klotski {
-namespace cases {
+namespace klotski::cases {
 
 /// Calculate all possible klotski heads.
 consteval static std::array<int, 12> case_heads() {
@@ -16,7 +16,7 @@ consteval static std::array<int, 12> case_heads() {
 }
 
 /// Check whether the combination of head and range is valid.
-static int check_range(int head, uint32_t range) noexcept {
+static int check_range(const int head, uint32_t range) noexcept {
     constexpr uint32_t M_1x1 = 0b00000001;
     constexpr uint32_t M_1x2 = 0b00000011;
     constexpr uint32_t M_2x1 = 0b00010001;
@@ -24,7 +24,7 @@ static int check_range(int head, uint32_t range) noexcept {
 
     uint32_t flags = M_2x2 << head; // fill 2x2 block
     for (int addr = 0, offset = 1; range; range >>= 2, ++offset) { // traverse every 2-bit
-        auto num = low_zero_num(~flags);
+        const auto num = low_zero_num(~flags);
         addr += num; // next unfilled block
         flags >>= num;
         switch (range & 0b11) {
@@ -50,7 +50,7 @@ static int check_range(int head, uint32_t range) noexcept {
 }
 
 /// Build all valid ranges of the specified head.
-void AllCases::build_cases(int head, Ranges &release) noexcept {
+void AllCases::build_cases(const int head, Ranges &release) noexcept {
     release.clear();
     release.reserve(ALL_CASES_NUM[head]);
     auto &basic_ranges = BasicRanges::instance().fetch();
@@ -127,5 +127,4 @@ void AllCases::build_parallel_async(Executor &&executor, Notifier &&callback) no
     }
 }
 
-} // namespace cases
-} // namespace klotski
+} // namespace klotski::cases

src/core/all_cases/all_cases.h

@@ -41,10 +41,12 @@
 #include <cstdint>
 #include <numeric>
 #include <functional>
+
 #include "utility.h"
 
-namespace klotski {
-namespace cases {
+namespace klotski::cases {
+
+// ----------------------------------------------------------------------------------------- //
 
 typedef uint32_t Range;
 typedef std::vector<Range> Ranges;
@@ -57,7 +59,7 @@ typedef std::function<void(std::function<void()>&&)> Executor;
 
 constexpr auto BASIC_RANGES_NUM = 7311921;
 
-constexpr std::array<int, 16> ALL_CASES_NUM {
+constexpr std::array ALL_CASES_NUM {
     2942906, 2260392, 2942906, 0,
     2322050, 1876945, 2322050, 0,
     2322050, 1876945, 2322050, 0,
@@ -76,7 +78,7 @@ public:
     const Ranges& fetch() noexcept;
     [[nodiscard]] bool is_available() const noexcept;
 
-    DISALLOW_COPY_AND_ASSIGN(BasicRanges);
+    MARK_INSTANCE(BasicRanges);
     static BasicRanges& instance() noexcept;
 
 private:
@@ -100,7 +102,7 @@ public:
     const RangesUnion& fetch() noexcept;
     [[nodiscard]] bool is_available() const noexcept;
 
-    DISALLOW_COPY_AND_ASSIGN(AllCases);
+    MARK_INSTANCE(AllCases);
     static AllCases& instance() noexcept;
 
 private:
@@ -114,7 +116,6 @@ private:
 
 // ----------------------------------------------------------------------------------------- //
 
-} // namespace cases
-} // namespace klotski
+} // namespace klotski::cases
 
-#include "inline_impl.h"
+#include "inline_impl.inl"

src/core/all_cases/basic_ranges.cc

@@ -1,9 +1,9 @@
 #include <list>
 #include <algorithm>
+
 #include "all_cases.h"
 
-namespace klotski {
-namespace cases {
+namespace klotski::cases {
 
 typedef std::vector<Range>::iterator RangeIter;
 typedef std::tuple<int, int, int, int> RangeType;
@@ -52,7 +52,7 @@ void BasicRanges::spawn_ranges(Ranges &ranges, int n1, int n2, int n3, int n4) n
 
     do { // full permutation traversal
         uint32_t range = 0;
-        for (auto x : series) // store every 2-bit
+        for (const auto x : series) // store every 2-bit
             (range <<= 2) |= x;
         ranges.emplace_back(range << offset);
     } while (next_permutation(series.begin(), series.end()));
@@ -87,7 +87,7 @@ void BasicRanges::build() noexcept {
     if (available_) {
         return; // reduce consumption of mutex
     }
-    std::lock_guard<std::mutex> guard(building_);
+    std::lock_guard guard(building_);
     if (available_) {
         return; // data is already available
     }
@@ -95,5 +95,4 @@ void BasicRanges::build() noexcept {
     available_ = true;
 }
 
-} // namespace cases
-} // namespace klotski
+} // namespace klotski::cases

src/core/all_cases/inline_impl.h → src/core/all_cases/inline_impl.inl

@@ -1,7 +1,6 @@
 #pragma once
 
-namespace klotski {
-namespace cases {
+namespace klotski::cases {
 
 // ----------------------------------------------------------------------------------------- //
 
@@ -47,5 +46,4 @@ inline bool AllCases::is_available() const noexcept {
 
 // ----------------------------------------------------------------------------------------- //
 
-} // namespace codec
-} // namespace klotski
+} // namespace klotski::codec

src/core/utils/utility.h

@@ -2,7 +2,7 @@
 
 #include <cstdint>
 
-#define DISALLOW_COPY_AND_ASSIGN(T) \
+#define MARK_INSTANCE(T)            \
     T(T &&) = delete;               \
     T(const T &) = delete;          \
     T& operator=(T &&) = delete;    \
@@ -10,7 +10,7 @@
 
 namespace klotski {
 
-inline int low_zero_num(uint32_t bin) {
+inline int low_zero_num(const uint32_t bin) {
     return __builtin_ctzl(bin);
 
     // TODO: using (bin ^ (bin - 1)) when non-builtin
@@ -19,14 +19,14 @@ inline int low_zero_num(uint32_t bin) {
     // return __builtin_popcount(~(bin ^ -bin)) - 1;
 }
 
-inline int low_zero_num(uint64_t bin) {
+inline int low_zero_num(const uint64_t bin) {
     return __builtin_ctzll(bin);
 
     // WARN: be aware of serious performance issues
     // return __builtin_popcount(~(bin ^ -bin)) - 1;
 }
 
-inline uint32_t range_reverse(uint32_t bin) noexcept {
+inline uint32_t range_reverse(uint32_t bin) {
 #if defined(__GNUC__) || defined(__clang__)
     bin = __builtin_bswap32(bin);
     // TODO: using `std::byteswap` (c++23)