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Adjust some assert(a == b) examples in std.bigint to improve DDoc runnable examples

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Some public unit tests are currently being translated into e.g.
https://dlang.org/phobos/std_bigint.html#.BigInt.opCast.3
---
// BigInts that fall somewhere between two non-infinite floats/doubles
// are rounded to the closer value when cast to float/double.
writeln(0x1.aaa_aaep+28f); // cast(float)BigInt(0x1aaa_aae7)
---
which is not confidence-inspiring. Additionally writeln will default to
scientific notation instead of hex format here.
This commit is contained in:
Nathan Sashihara 2021-03-17 23:18:58 -07:00 • committed by The Dlang Bot
parent 368273279e
commit afe9cb5e1a
1 changed files with 27 additions and 24 deletions
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51
std/bigint.d
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@ -881,13 +881,16 @@ public:
///
@system unittest
{
assert(0x1.abcd_e8p+124f == cast(float) BigInt("0x1abc_de80_0000_0000_0000_0000_0000_0000"));
assert(0x1.abcd_ef12_3456p+124 == cast(double) BigInt("0x1abc_def1_2345_6000_0000_0000_0000_0000"));
assert(0x1.abcd_ef12_3456p+124L == cast(real) BigInt("0x1abc_def1_2345_6000_0000_0000_0000_0000"));
assert(cast(float) BigInt("35540592535949172786332045140593475584")
== 35540592535949172786332045140593475584.0f);
assert(cast(double) BigInt("35540601499647381470685035515422441472")
== 35540601499647381470685035515422441472.0);
assert(cast(real) BigInt("35540601499647381470685035515422441472")
== 35540601499647381470685035515422441472.0L);
assert(-0x1.3456_78p+108f == cast(float) BigInt("-0x1345_6780_0000_0000_0000_0000_0000"));
assert(-0x1.3456_78ab_cdefp+108 == cast(double) BigInt("-0x1345_678a_bcde_f000_0000_0000_0000"));
assert(-0x1.3456_78ab_cdefp+108L == cast(real) BigInt("-0x1345_678a_bcde_f000_0000_0000_0000"));
assert(cast(float) BigInt("-0x1345_6780_0000_0000_0000_0000_0000") == -0x1.3456_78p+108f );
assert(cast(double) BigInt("-0x1345_678a_bcde_f000_0000_0000_0000") == -0x1.3456_78ab_cdefp+108 );
assert(cast(real) BigInt("-0x1345_678a_bcde_f000_0000_0000_0000") == -0x1.3456_78ab_cdefp+108L);
}
/// Rounding when casting to floating point
@ -900,42 +903,42 @@ public:
// BigInts that fall somewhere between two non-infinite floats/doubles
// are rounded to the closer value when cast to float/double.
assert(0x1.aaa_aaep+28f == cast(float) BigInt(0x1aaa_aae7));
assert(0x1.aaa_ab0p+28f == cast(float) BigInt(0x1aaa_aaff));
assert(-0x1.aaaaaep+28f == cast(float) BigInt(-0x1aaa_aae7));
assert(-0x1.aaaab0p+28f == cast(float) BigInt(-0x1aaa_aaff));
assert(cast(float) BigInt(0x1aaa_aae7) == 0x1.aaa_aaep+28f);
assert(cast(float) BigInt(0x1aaa_aaff) == 0x1.aaa_ab0p+28f);
assert(cast(float) BigInt(-0x1aaa_aae7) == -0x1.aaaaaep+28f);
assert(cast(float) BigInt(-0x1aaa_aaff) == -0x1.aaaab0p+28f);
assert(0x1.aaa_aaaa_aaaa_aa00p+60 == cast(double) BigInt(0x1aaa_aaaa_aaaa_aa77));
assert(0x1.aaa_aaaa_aaaa_ab00p+60 == cast(double) BigInt(0x1aaa_aaaa_aaaa_aaff));
assert(-0x1.aaa_aaaa_aaaa_aa00p+60 == cast(double) BigInt(-0x1aaa_aaaa_aaaa_aa77));
assert(-0x1.aaa_aaaa_aaaa_ab00p+60 == cast(double) BigInt(-0x1aaa_aaaa_aaaa_aaff));
assert(cast(double) BigInt(0x1aaa_aaaa_aaaa_aa77) == 0x1.aaa_aaaa_aaaa_aa00p+60);
assert(cast(double) BigInt(0x1aaa_aaaa_aaaa_aaff) == 0x1.aaa_aaaa_aaaa_ab00p+60);
assert(cast(double) BigInt(-0x1aaa_aaaa_aaaa_aa77) == -0x1.aaa_aaaa_aaaa_aa00p+60);
assert(cast(double) BigInt(-0x1aaa_aaaa_aaaa_aaff) == -0x1.aaa_aaaa_aaaa_ab00p+60);
// BigInts that fall exactly between two non-infinite floats/doubles
// are rounded away from zero when cast to float/double. (Note that
// in most environments this is NOT the same rounding rule rule used
// when casting int/long to float/double.)
assert(0x1.aaa_ab0p+28f == cast(float) BigInt(0x1aaa_aaf0));
assert(-0x1.aaaab0p+28f == cast(float) BigInt(-0x1aaa_aaf0));
assert(cast(float) BigInt(0x1aaa_aaf0) == 0x1.aaa_ab0p+28f);
assert(cast(float) BigInt(-0x1aaa_aaf0) == -0x1.aaaab0p+28f);
assert(0x1.aaa_aaaa_aaaa_ab00p+60 == cast(double) BigInt(0x1aaa_aaaa_aaaa_aa80));
assert(-0x1.aaa_aaaa_aaaa_ab00p+60 == cast(double) BigInt(-0x1aaa_aaaa_aaaa_aa80));
assert(cast(double) BigInt(0x1aaa_aaaa_aaaa_aa80) == 0x1.aaa_aaaa_aaaa_ab00p+60);
assert(cast(double) BigInt(-0x1aaa_aaaa_aaaa_aa80) == -0x1.aaa_aaaa_aaaa_ab00p+60);
// BigInts that are bounded on one side by the largest positive or
// most negative finite float/double and on the other side by infinity
// or -infinity are rounded as if in place of infinity was the value
// `2^^(T.max_exp)` when cast to float/double.
assert(float.infinity == cast(float) BigInt("999_999_999_999_999_999_999_999_999_999_999_999_999"));
assert(-float.infinity == cast(float) BigInt("-999_999_999_999_999_999_999_999_999_999_999_999_999"));
assert(cast(float) BigInt("999_999_999_999_999_999_999_999_999_999_999_999_999") == float.infinity);
assert(cast(float) BigInt("-999_999_999_999_999_999_999_999_999_999_999_999_999") == -float.infinity);
assert(double.infinity > cast(double) BigInt("999_999_999_999_999_999_999_999_999_999_999_999_999"));
assert(real.infinity > cast(real) BigInt("999_999_999_999_999_999_999_999_999_999_999_999_999"));
assert(cast(double) BigInt("999_999_999_999_999_999_999_999_999_999_999_999_999") < double.infinity);
assert(cast(real) BigInt("999_999_999_999_999_999_999_999_999_999_999_999_999") < real.infinity);
}
@safe unittest
{
// Test exponent overflow is correct.
assert(0x1.000000p+29f == cast(float) BigInt(0x1fffffff));
assert(0x1.000000p+61 == cast(double) BigInt(0x1fff_ffff_ffff_fff0));
assert(cast(float) BigInt(0x1fffffff) == 0x1.000000p+29f);
assert(cast(double) BigInt(0x1fff_ffff_ffff_fff0) == 0x1.000000p+61);
}
private T toFloat(T, string roundingMode)() @safe nothrow @nogc const