Replace Boost unit test with Catch2.

CMakeLists.txt

@@ -69,60 +69,5 @@ set(gcc_like $<OR:${gcc},${clang})
 if (MVPOLYNOMIAL_BUILD_TESTS)
   enable_testing()
 
-  set(boost_test_dependencies
-    algorithm
-    array
-    assert
-    bind
-    config
-    concept_check
-    container_hash
-    conversion
-    core
-    detail
-    describe
-    exception
-    function
-    functional
-    function_types
-    fusion
-    io
-    iterator
-    mp11
-    mpl
-    numeric_conversion
-    optional
-    predef
-    preprocessor
-    regex
-    range
-    smart_ptr
-    static_assert
-    throw_exception
-    tuple
-    typeof
-    type_traits
-    unordered
-    utility
-  )
-
-  foreach(deplib ${boost_test_dependencies})
-    FetchContent_Declare(
-      ${deplib}
-      GIT_REPOSITORY https://github.com/boostorg/${deplib}.git
-      GIT_TAG        boost-1.89.0
-      OVERRIDE_FIND_PACKAGE
-    )
-    FetchContent_MakeAvailable(${deplib})
-  endforeach()
-
-  FetchContent_Declare(
-    boost_unit_test
-    GIT_REPOSITORY https://github.com/boostorg/test.git
-    GIT_TAG        boost-1.89.0
-    OVERRIDE_FIND_PACKAGE
-  )
-  FetchContent_MakeAvailable(boost_unit_test)
-
   add_subdirectory(test)
 endif()

include/mvPolynomial/mvPolynomial.hpp

@@ -365,6 +365,8 @@ class MVPolynomial final {
     auto comparer = l.key_comp();
 
     auto mul = MVPolynomial(l.get_allocator());
+    // Clear
+    mul.erase(mul.begin());
     // Calculate all product of each l's term and r's term.
     for (const auto& l_p : l) {
       const auto& [l_idx, l_v] = l_p;

test/CMakeLists.txt

@@ -1,3 +1,11 @@
+FetchContent_Declare(
+  Catch2
+  GIT_REPOSITORY https://github.com/catchorg/Catch2.git
+  GIT_TAG        b3fb4b9feafcd8d91c5cb510a4775143fdbef02f # v3.11.0
+  OVERRIDE_FIND_PACKAGE
+)
+FetchContent_MakeAvailable(Catch2)
+
 add_executable(mvPolynomial_test mvPolynomial_test.cpp)
 target_compile_options(
   mvPolynomial_test
@@ -10,7 +18,7 @@ target_link_libraries(
   mvPolynomial_test
   PRIVATE
     ${PROJECT_NAME}
-    Boost::unit_test_framework
+    Catch2::Catch2WithMain
 )
 
 add_test(NAME mvPolynomial_test COMMAND mvPolynomial_test)