module axfinance.api.currencies;

import std.array, std.stdio, std.system, std.bigint, std.conv;


class Currencies
{
	public:
		this(ulong pf)
		{
			exponent(pf);
		}
		bool integer(BigInt pb)
		{
			zInt = pb;
			return true;
		}
		string value()
		{
			string res = to!string(zInt);
			insertInPlace(res, res.length - zExp,".");
			return res;
		}
	private:
		bool exponent(ulong pe)
		{
			zExp = pe;
			return true;
		}
		BigInt zInt;
		ulong zExp;
}

unittest
{
	double d1 = 45.67;
	immutable LIM_FIAT = 2, LIM_EXCH = 6, LIM_CRYP = 8;
	auto c = [	"BTC":["N-01":new Currencies(LIM_CRYP), "N-02":new Currencies(LIM_CRYP), "SUM1":new Currencies(LIM_CRYP)],
			"CNY":["N-01":new Currencies(LIM_FIAT), "N-02":new Currencies(LIM_EXCH), "N-03":new Currencies(LIM_CRYP), "SUM1":new Currencies(LIM_CRYP), "SUM2":new Currencies(LIM_CRYP)]];
//	 EUR, LTC, RUB;

	c["BTC"]["N-01"] = 1.00000002;//Error: cannot implicitly convert expression (1) of type double to axfinance.api.currencies.Currencies
	c["BTC"]["N-02"] = 15.00000002+"13455565.45665435";
	c["BTC"]["SUM1"] = c["BTC"]["N-01"] + c["BTC"]["N-02"];
	assert(c["BTC"]["SUM1"] == "13455581.45665437");
	c["CNY"]["N-01"] = 1.02;
	c["CNY"]["N-02"] = "0.01";
	c["CNY"]["N-03"] = "0.00000001";
	c["CNY"]["SUM1"] = c["CNY"]["N-01"] + c["CNY"]["N-02"];
	assert(c["CNY"]["SUM1"] == "1.03");
	assert(to!double(c["CNY"]["SUM1"]) == 1.03);
	c["CNY"]["SUM2"] = c["CNY"]["N-01"] + c["CNY"]["N-03"];
	assert(c["CNY"]["SUM2"] == "1.02000001");
}

What do I need to learn?

On Friday, 30 January 2015 at 20:34:53 UTC, RuZzz wrote:
> What do I need to learn?

> c["BTC"]["N-01"] = 1.00000002;//Error: cannot implicitly convert
expression (1) of type double to axfinance.api.currencies.Currencies

As I see it, there is no constructor in your class with a double argument.
So you cannot assign a double (1.00000002)
to a Currencies struct (c["BTC"]["N-01"]).

How to get amount of digit after point in a double for to get integer from a double?
    assert(amountAfterPoint(1.456) == 3);
    assert(amountAfterPoint(0.00006) == 5);

without to!string

On Saturday, 31 January 2015 at 12:07:23 UTC, RuZzz wrote:
> How to get amount of digit after point in a double for to get integer from a double?
>     assert(amountAfterPoint(1.456) == 3);
>     assert(amountAfterPoint(0.00006) == 5);

How about a loop like

import std.stdio;

void main(){
	writefln("%s", 1.45.numDigits);// prints 2
	writefln("%s", 1.452343.numDigits);// prints 6
	writefln("%s", 1.0.numDigits);// prints 0
}

long numDigits(double num){
     long i=0;
     double n=num;
     while(true){
	if(n - (cast(long)n) == 0){
		return i;
	}
	i++;
         n *= 10;
     }
}

Thanks. Do I need to use rational fractions for the Currencies
class?

I want to understand the correct architecture of the class.

On Saturday, 31 January 2015 at 13:45:22 UTC, RuZzz wrote:
> I want to understand the correct architecture of the class.

Sorry, you still did not state your problem (or what you are trying to achieve) clearly.
Writing down a clear problem description is likely to get you halfway to the solution.

The next version, which does not work:
https://bpaste.net/show/b9c85de68d07