晋太元中,武陵人捕鱼为业。缘溪行,忘路之远近。忽逢桃花林,夹岸数百步,中无杂树,芳草鲜美,落英缤纷。渔人甚异之,复前行,欲穷其林。 林尽水源,便得一山,山有小口,仿佛若有光。便舍船,从口入。初极狭,才通人。复行数十步,豁然开朗。土地平旷,屋舍俨然,有良田、美池、桑竹之属。阡陌交通,鸡犬相闻。其中往来种作,男女衣着,悉如外人。黄发垂髫,并怡然自乐。 见渔人,乃大惊,问所从来。具答之。便要还家,设酒杀鸡作食。村中闻有此人,咸来问讯。自云先世避秦时乱,率妻子邑人来此绝境,不复出焉,遂与外人间隔。问今是何世,乃不知有汉,无论魏晋。此人一一为具言所闻,皆叹惋。余人各复延至其家,皆出酒食。停数日,辞去。此中人语云:“不足为外人道也。”(间隔 一作:隔绝) 既出,得其船,便扶向路,处处志之。及郡下,诣太守,说如此。太守即遣人随其往,寻向所志,遂迷,不复得路。 南阳刘子骥,高尚士也,闻之,欣然规往。未果,寻病终。后遂无问津者。
| DIR:/opt/alt/ruby31/include/ruby/internal/arithmetic/ |
| Current File : //opt/alt/ruby31/include/ruby/internal/arithmetic/double.h |
#ifndef RBIMPL_ARITHMETIC_DOUBLE_H /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_ARITHMETIC_DOUBLE_H
/**
* @file
* @author Ruby developers <ruby-core@ruby-lang.org>
* @copyright This file is a part of the programming language Ruby.
* Permission is hereby granted, to either redistribute and/or
* modify this file, provided that the conditions mentioned in the
* file COPYING are met. Consult the file for details.
* @warning Symbols prefixed with either `RBIMPL` or `rbimpl` are
* implementation details. Don't take them as canon. They could
* rapidly appear then vanish. The name (path) of this header file
* is also an implementation detail. Do not expect it to persist
* at the place it is now. Developers are free to move it anywhere
* anytime at will.
* @note To ruby-core: remember that this header can be possibly
* recursively included from extension libraries written in C++.
* Do not expect for instance `__VA_ARGS__` is always available.
* We assume C99 for ruby itself but we don't assume languages of
* extension libraries. They could be written in C++98.
* @brief Arithmetic conversion between C's `double` and Ruby's.
*/
#include "ruby/internal/attr/pure.h"
#include "ruby/internal/dllexport.h"
#include "ruby/internal/value.h"
#define NUM2DBL rb_num2dbl /**< @old{rb_num2dbl} */
#define RFLOAT_VALUE rb_float_value /**< @old{rb_float_value} */
#define DBL2NUM rb_float_new /**< @old{rb_float_new} */
RBIMPL_SYMBOL_EXPORT_BEGIN()
/**
* Converts an instance of ::rb_cNumeric into C's `double`.
*
* @param[in] num Something numeric.
* @exception rb_eTypeError `num` is not a numeric.
* @return The passed value converted into C's `double`.
*/
double rb_num2dbl(VALUE num);
RBIMPL_ATTR_PURE()
/**
* Extracts its double value from an instance of ::rb_cFloat.
*
* @param[in] num An instance of ::rb_cFloat.
* @pre Must not pass anything other than a Fixnum.
* @return The passed value converted into C's `double`.
*/
double rb_float_value(VALUE num);
/**
* Converts a C's `double` into an instance of ::rb_cFloat.
*
* @param[in] d Arbitrary `double` value.
* @return An instance of ::rb_cFloat.
*/
VALUE rb_float_new(double d);
/**
* Identical to rb_float_new(), except it does not generate Flonums.
*
* @param[in] d Arbitrary `double` value.
* @return An instance of ::rb_cFloat.
*
* @internal
*
* @shyouhei has no idea why it is here.
*/
VALUE rb_float_new_in_heap(double d);
RBIMPL_SYMBOL_EXPORT_END()
#endif /* RBIMPL_ARITHMETIC_DOUBLE_H */
|