D
                            Threshold of return slots, above which
                              <b>malloc()</b> is used by the POSIX API
  PCRE_CONFIG_STACKRECURSE  Recursion implementation (1=stack 0=heap)
  PCRE_CONFIG_UTF16         Availability of UTF-16 support (1=yes
                               0=no); option for <b>pcre16_config()</b>
  PCRE_CONFIG_UTF32         Availability of UTF-32 support (1=yes
                               0=no); option for <b>pcre32_config()</b>
  PCRE_CONFIG_UTF8        