Remove the deprecated POSIX API and make Boost.Regex header only.

.github/workflows/ci.yml

@@ -90,7 +90,7 @@ jobs:
       - name: Install packages
         run: sudo apt install libicu-dev
       - name: Test
-        run: ${{ matrix.compiler }} -std=${{ matrix.standard }}  -I../../include *.cpp ../../src/*.cpp -o regress && ./regress
+        run: ${{ matrix.compiler }} -std=${{ matrix.standard }}  -I../../include *.cpp -o regress && ./regress
         working-directory: ./test/regress
   ubuntu-jammy-clang:
     runs-on: ubuntu-22.04

build.jam

@@ -20,11 +20,10 @@ project /boost/regex
     ;
 
 explicit
-    [ alias boost_regex : build//boost_regex ]
+    [ alias boost_regex : : : : <include>include <library>$(boost_dependencies) ]
     [ alias all : boost_regex example test ]
     ;
 
 call-if : boost-library regex
-    : install boost_regex
     ;