:relfileprefix: ../../../
[#12EAA76EB6E2BFA59C1F282C8C941D699D6B9E18]

= Function hexdig_value

pass:v,q[Return the decimal value of a hex character]


== Synopsis

Declared in header `</boost/url/grammar/hexdig_chars.hpp#L123[boost/url/grammar/hexdig_chars.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
signed char
hexdig_value(char ch) noexcept;
----

== Description

pass:v,q[This function returns the decimal] pass:v,q[value of a hexadecimal character,]
pass:v,q[or -1 if the argument is not a]
pass:v,q[valid hexadecimal digit.]

=== BNF
[,cpp]
----
HEXDIG      = DIGIT
            / "A" / "B" / "C" / "D" / "E" / "F"
            / "a" / "b" / "c" / "d" / "e" / "f"
----



== Return Value

* `signed char` 


== Parameters

|===
| Name | Type 

| *ch*
| `char`

|===