valgrind warnnings

[lynch1981]

When I use the application tracked by valgrind, got lots of valgrind warnnings like this

my code like this

static jp::Regex e(R"(\b0x[0-9a-f]{3,}\b)", "S");
asm_txt = e.replace(asm_txt, "HEX", "g");

When I change it to the following method, the warning can be eliminated, but when I use this code in a loop, the regular expression will be JIT compiled repeatedly.

static jp::Regex e(R"(\b0x[0-9a-f]{3,}\b)");
asm_code = e.addModifier("S").replace(asm_code, "HEX", "g");

bash valgrind --track-origins=yes --leak-check=full -q my_program

==71672== Conditional jump or move depends on uninitialised value(s)
==71672== at 0x5244B3F: ???
==71672== by 0x5B7FD37: ???
==71672== Uninitialised value was created by a heap allocation
==71672== at 0x4845FF5: operator new(unsigned long) (vg_replace_malloc.c:422)
==71672== by 0x4A46B89: std::__cxx11::basic_string<char, std::char_traits, std::allocator >::_M_assign(std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&) (basic_string.tcc:284)
==71672== by 0x40B4D1: assign (basic_string.h:1571)
==71672== by 0x40B4D1: operator= (basic_string.h:805)
==71672== by 0x40B4D1: setSubject (jpcre2.hpp:3245)
==71672== by 0x40B4D1: replace (jpcre2.hpp:4312)