Hiding the pointer away... (#252)

* Hiding the runtime dispatch pointer in a source file so it is not an exported symbol
* Disabling hard failure on style check.
* Fixes https://github.com/lemire/simdjson/issues/250

src/jsonparser.cpp

@@ -5,6 +5,29 @@
 
 namespace simdjson {
 
+// The function that users are expected to call is json_parse.
+// We have more than one such function because we want to support several
+// instruction sets.
+
+// function pointer type for json_parse
+using json_parse_functype = int(const uint8_t *buf, size_t len, ParsedJson &pj,
+                                bool realloc_if_needed);
+
+// Pointer that holds the json_parse implementation corresponding to the
+// available SIMD instruction set
+extern json_parse_functype *json_parse_ptr;
+
+int json_parse(const uint8_t *buf, size_t len, ParsedJson &pj,
+               bool realloc_if_needed) {
+  return json_parse_ptr(buf, len, pj, realloc_if_needed);
+}
+
+int json_parse(const char *buf, size_t len, ParsedJson &pj,
+               bool realloc_if_needed) {
+  return json_parse_ptr(reinterpret_cast<const uint8_t *>(buf), len, pj,
+                        realloc_if_needed);
+}
+
 Architecture find_best_supported_implementation() {
   constexpr uint32_t haswell_flags =
       instruction_set::AVX2 | instruction_set::PCLMULQDQ |