/*?Example?illustrating?how?to?use?mpfr_can_round.?*/

/*
Copyright?2016-2019?Free?Software?Foundation?Inc.
Contributed?by?the?AriC?and?Caramba?projects?INRIA.

This?file?is?part?of?the?GNU?MPFR?Library.

The?GNU?MPFR?Library?is?free?software;?you?can?redistribute?it?and/or?modify
it?under?the?terms?of?the?GNU?Lesser?General?Public?License?as?published?by
the?Free?Software?Foundation;?either?version?3?of?the?License?or?（at?your
option）?any?later?version.

The?GNU?MPFR?Library?is?distributed?in?the?hope?that?it?will?be?useful?but
WITHOUT?ANY?WARRANTY;?without?even?the?implied?warranty?of?MERCHANTABILITY
or?FITNESS?FOR?A?PARTICULAR?PURPOSE.??See?the?GNU?Lesser?General?Public
License?for?more?details.

You?should?have?received?a?copy?of?the?GNU?Lesser?General?Public?License
along?with?the?GNU?MPFR?Library;?see?the?file?COPYING.LESSER.??If?not?see
https://www.gnu.org/licenses/?or?write?to?the?Free?Software?Foundation?Inc.
51?Franklin?St?Fifth?Floor?Boston?MA?02110-1301?USA.
*/

#include?
#include?

int
main?（void）
{
??mpfr_t?x?y;
??mpfr_prec_t?px?=?53?py?=?50;
??mpfr_rnd_t?r1?r2;
??int?ok;

??/*?Given?an?approximation?of?Pi?to?px?bits?computed?with?rounding?mode?r1
?????we?call?mpfr_can_round（）?to?see?if?we?can?deduced?the?correct?rounding
?????of?Pi?to?py?bits?with?rounding?mode?r2.
?????The?error?is?at?most?1?=?2^0?ulp.?This?translates?into?err?=?prec（x）.?*/
??mpfr_init2?（x?px）;
??mpfr_init2?（y?py）;
??for?（r1?=?0;?r1?????{
??????mpfr_const_pi?（x?r1）;
??????printf?（“r1=%s?approx=“?mpfr_print_rnd_mode?（r1））;
??????mpfr_out_str?（stdout?2?0?x?MPFR_RNDN）;
??????printf?（“\n“）;
??????for?（r2?=?0;?r2?????????{
??????????ok?=?mpfr_can_round?（x?mpfr_get_prec?（x）?r1?r2?py）;
??????????printf?（“r2=%s?ok=%d“?mpfr_print_rnd_mode?（r2）?ok）;
??????????if?（ok）
????????????{
??????????????mpfr_set?（y?x?r2）;
??????????????printf?（“???“）;
??????????????mpfr_out_str?（stdout?2?0?y?MPFR_RNDN）;
????????????}
??????????printf?（“\n“）;
????????}
????}
??mpfr_clear?（x）;
??mpfr_clear?（y）;
??return?0;
}