1 files changed, 102 insertions, 0 deletions
diff --git a/tests/cpp/include/doubl2str.h b/tests/cpp/include/doubl2str.h
new file mode 100644
index 0000000..1a5e3fc
--- /dev/null
+++ b/tests/cpp/include/doubl2str.h
@@ -0,0 +1,102 @@
+/**
+ *
+ *  double -> string
+ *
+ */
+
+
+
+char num2char(unsigned int num) 
+{
+	switch(num)
+	{
+	    case 0:
+	        return '0';
+	    case 1:
+	        return '1';
+	    case 2:
+	        return '2';
+	    case 3:
+	        return '3';
+	    case 4:
+	        return '4';
+	    case 5:
+	        return '5';
+	    case 6:
+	        return '6';
+	    case 7:
+	        return '7';
+	    case 8:
+	        return '8';
+	    case 9:
+	        return '9';
+	}
+
+	//return '\0';
+	return '-';
+}
+
+std::string double2str(long double D)
+{
+	int sign = (D > 0) ? 1 : (D*=-1.0, -1);
+	unsigned long long int Ceil = D;
+	
+	// if D is ceil
+	if(Ceil == D)
+	{
+		return std::to_string( (long long)(D*sign) );
+	}
+
+	// size of result buffer
+	const int bs = 32;
+	
+	// size of temporary buffer
+	const int pw = 16;
+	// Temporary buffer
+	char buf[pw];
+	// Result buffer
+	char rez[bs];
+
+	int i, size = 0;
+	// set sign
+	if(sign < 0) rez[size++] = '-';
+
+	// set ceil
+	std::string sceil = std::to_string(Ceil);
+	const char * bceil = sceil.c_str();
+	int sceillen = sceil.size();
+	for(i = 0; i < sceillen; i++)
+	{
+		rez[size++] = bceil[i];
+	}
+
+	// set point
+	rez[size++] = '.';
+	
+	unsigned long long int I =  D * 10000000000000000; // D * 10**pw
+	// .14159265359 -> 14159265359000000
+	I -= Ceil * 10000000000000000;
+
+	// Remove the tail of zeros
+	// 14159265359000000 -> 14159265359
+	while(0 == I % 10) I /= 10;
+
+	int ind = 0;
+	while(I > 0)
+	{
+		buf[ind++] = num2char(I%10);
+		I = (I - I%10) / 10;
+	}
+
+	// set fraction part
+	for(i = 0; i < ind; i++)
+	{
+		rez[size] = buf[ind-i-1];
+		size++;
+	}
+
+	return std::string(rez, size);
+	//rez[size] = '\0';
+}
+
+