Differential D572 Diff 1451 src/utilstrencodings.h

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src/utilstrencodings.h

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	* Parse number as fixed point according to JSON number syntax.			* Parse number as fixed point according to JSON number syntax.
	* See http://json.org/number.gif			* See http://json.org/number.gif
	* @returns true on success, false on error.			* @returns true on success, false on error.
	* @note The result must be in the range (-10^18,10^18), otherwise an overflow			* @note The result must be in the range (-10^18,10^18), otherwise an overflow
	* error will trigger.			* error will trigger.
	*/			*/
	bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out);			bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out);

				/**
				* Convert from one power-of-2 number base to another.
				* If padding is enabled, this always return true. If not, then it returns true
				* of all the bits of the input are encoded in the output.
				*/
				template <int frombits, int tobits, bool pad, typename O, typename I>
				bool ConvertBits(O &out, I it, I end) {
				size_t acc = 0;
				size_t bits = 0;
				constexpr size_t maxv = (1 << tobits) - 1;
				constexpr size_t max_acc = (1 << (frombits + tobits - 1)) - 1;
				while (it != end) {
				acc = ((acc << frombits) \| *it) & max_acc;
				bits += frombits;
				while (bits >= tobits) {
				bits -= tobits;
				out.push_back((acc >> bits) & maxv);
				}
				++it;
				}

				// We have remaining bits to encode but do not pad.
				if (!pad && bits) {
				return false;
				}

				// We have remaining bits to encode so we do pad.
				if (pad && bits) {
				out.push_back((acc << (tobits - bits)) & maxv);
				}

				return true;
				}

	#endif // BITCOIN_UTILSTRENCODINGS_H			#endif // BITCOIN_UTILSTRENCODINGS_H