Class, constructor and inherance.

[holo via Digitalmars-d-learn]

Hello

I'm trying to write my first class. I want to use it as module 
and build anothers on top of it. I read that default functions 
attributes are not inherited. Is it that same for constructor? 
This is how my class (not finished) is looking right now:

class credential
{
	auto accessKey = environment.get["AWS_ACCESS_KEY"];
	auto secretKey = environment.get["AWS_SECRET_KEY"];
}

class sigv4 : credential
{
	public:
		string method;
		string service;
		string host;
		string region;
		string endpoint;
		string request_parameters;
		string payload;

	private:
		const algorithm = "AWS4-HMAC-SHA256";

		auto currentClock = Clock.currTime(UTC());
		auto currentDate = cast(Date)currentClock;
		auto curDateStr = currentDate.toISOString;
		auto currentTime = cast(TimeOfDay)currentClock;
		auto curTimeStr = currentTime.toISOString;
		auto xamztime = curDateStr ~ "T" ~ curTimeStr ~ "Z";

		auto hmac_sha256(ubyte[] key, ubyte[] msg)
		{
			auto hmac = hmac!SHA256(key);
			hmac.put(msg);
			auto digest = hmac.finish;

			return digest;
		}

		auto getSignatureKey(string key, string dateStamp, string 
regionName, string serviceName)
		{
			ubyte[] kString = cast(ubyte[])("AWS4" ~ key);
			auto kDate = sign(kString, cast(ubyte[])dateStamp);
			auto kRegion = sign(kDate, cast(ubyte[])regionName);
			auto kService = sign(kRegion,  cast(ubyte[])serviceName);
			auto kSigning = sign(kService, cast(ubyte[])"aws4_request");

			return kSigning;
		}

		auto getCanonicalRequest(string canonicalURI, string 
canonicalQueryString, string canonicalHeaderString, string 
signedHeaders)
		{
			string payloadHash = sha256Of("").toHexString.toLower;
			string canonicalRequest = method ~ "\n" ~ canonicalURI ~ "\n" 
~ canonicalQueryString ~ "\n" ~ canonicalHeadersString ~ "\n" ~ 
signedHeaders ~ "\n" ~ payloadHash;
		}

		this()
		{
			
		}
}

I need to set all variables by defaults values from "public" and 
all needed by function "getCanonicalRequest". But if i will use 
that class to build another should i set defaults again? If yes 
is there some solution for it?

//holo