diff --git a/dlls/msvcirt/msvcirt.c b/dlls/msvcirt/msvcirt.c
index 99388fe64b8..9c36e691ef7 100644
--- a/dlls/msvcirt/msvcirt.c
+++ b/dlls/msvcirt/msvcirt.c
@@ -4225,13 +4225,44 @@ iostream* __thiscall iostream_scalar_dtor(ios *base, unsigned int flags)
     return this;
 }
 
+static iostream* iostream_internal_copy_ctor(iostream *this, const iostream *copy, const vtable_ptr *vtbl, BOOL virt_init)
+{
+    ios *base, *base_copy = istream_get_ios(&copy->base1);
+
+    if (virt_init) {
+        this->base1.vbtable = iostream_vbtable_istream;
+        this->base2.vbtable = iostream_vbtable_ostream;
+        base = istream_get_ios(&this->base1);
+        ios_copy_ctor(base, base_copy);
+    } else
+        base = istream_get_ios(&this->base1);
+    ios_init(base, base_copy->sb);
+    istream_ctor(&this->base1, FALSE);
+    ostream_ctor(&this->base2, FALSE);
+    base->vtable = vtbl;
+    return this;
+}
+
+static iostream* iostream_internal_sb_ctor(iostream *this, streambuf *sb, const vtable_ptr *vtbl, BOOL virt_init)
+{
+    ios *base;
+
+    iostream_ctor(this, virt_init);
+    base = istream_get_ios(&this->base1);
+    if (sb)
+        ios_init(base, sb);
+    base->vtable = vtbl;
+    base->delbuf = 1;
+    return this;
+}
+
 /* ??0strstream@@QAE@ABV0@@Z */
 /* ??0strstream@@QEAA@AEBV0@@Z */
 DEFINE_THISCALL_WRAPPER(strstream_copy_ctor, 12)
 iostream* __thiscall strstream_copy_ctor(iostream *this, const iostream *copy, BOOL virt_init)
 {
-    FIXME("(%p %p %d) stub\n", this, copy, virt_init);
-    return this;
+    TRACE("(%p %p %d)\n", this, copy, virt_init);
+    return iostream_internal_copy_ctor(this, copy, &MSVCP_strstream_vtable, virt_init);
 }
 
 /* ??0strstream@@QAE@PADHH@Z */
@@ -4239,8 +4270,17 @@ iostream* __thiscall strstream_copy_ctor(iostream *this, const iostream *copy, B
 DEFINE_THISCALL_WRAPPER(strstream_buffer_ctor, 20)
 iostream* __thiscall strstream_buffer_ctor(iostream *this, char *buffer, int length, int mode, BOOL virt_init)
 {
-    FIXME("(%p %p %d %d %d) stub\n", this, buffer, length, mode, virt_init);
-    return this;
+    strstreambuf *ssb = MSVCRT_operator_new(sizeof(strstreambuf));
+
+    TRACE("(%p %p %d %d %d)\n", this, buffer, length, mode, virt_init);
+
+    if (ssb) {
+        strstreambuf_buffer_ctor(ssb, buffer, length, buffer);
+        if ((mode & OPENMODE_out) && (mode & (OPENMODE_app|OPENMODE_ate)))
+            ssb->base.pptr = buffer + strlen(buffer);
+        return iostream_internal_sb_ctor(this, &ssb->base, &MSVCP_strstream_vtable, virt_init);
+    }
+    return iostream_internal_sb_ctor(this, NULL, &MSVCP_strstream_vtable, virt_init);
 }
 
 /* ??0strstream@@QAE@XZ */
@@ -4248,8 +4288,15 @@ iostream* __thiscall strstream_buffer_ctor(iostream *this, char *buffer, int len
 DEFINE_THISCALL_WRAPPER(strstream_ctor, 8)
 iostream* __thiscall strstream_ctor(iostream *this, BOOL virt_init)
 {
-    FIXME("(%p %d) stub\n", this, virt_init);
-    return this;
+    strstreambuf *ssb = MSVCRT_operator_new(sizeof(strstreambuf));
+
+    TRACE("(%p %d)\n", this, virt_init);
+
+    if (ssb) {
+        strstreambuf_ctor(ssb);
+        return iostream_internal_sb_ctor(this, &ssb->base, &MSVCP_strstream_vtable, virt_init);
+    }
+    return iostream_internal_sb_ctor(this, NULL, &MSVCP_strstream_vtable, virt_init);
 }
 
 /* ?pcount@strstream@@QBEHXZ */
diff --git a/dlls/msvcirt/tests/msvcirt.c b/dlls/msvcirt/tests/msvcirt.c
index ed87a237603..de5af0d0e81 100644
--- a/dlls/msvcirt/tests/msvcirt.c
+++ b/dlls/msvcirt/tests/msvcirt.c
@@ -404,6 +404,14 @@ static void (*__thiscall p_iostream_vbase_dtor)(iostream*);
 static iostream* (*__thiscall p_iostream_assign_sb)(iostream*, streambuf*);
 static iostream* (*__thiscall p_iostream_assign)(iostream*, const iostream*);
 
+/* strstream */
+static iostream* (*__thiscall p_strstream_copy_ctor)(iostream*, const iostream*, BOOL);
+static iostream* (*__thiscall p_strstream_buffer_ctor)(iostream*, char*, int, int, BOOL);
+static iostream* (*__thiscall p_strstream_ctor)(iostream*, BOOL);
+static void (*__thiscall p_strstream_dtor)(ios*);
+static void (*__thiscall p_strstream_vbase_dtor)(iostream*);
+static iostream* (*__thiscall p_strstream_assign)(iostream*, const iostream*);
+
 /* Iostream_init */
 static void* (*__thiscall p_Iostream_init_ios_ctor)(void*, ios*, int);
 
@@ -681,6 +689,13 @@ static BOOL init(void)
         SET(p_iostream_assign_sb, "??4iostream@@IEAAAEAV0@PEAVstreambuf@@@Z");
         SET(p_iostream_assign, "??4iostream@@IEAAAEAV0@AEAV0@@Z");
 
+        SET(p_strstream_copy_ctor, "??0strstream@@QEAA@AEBV0@@Z");
+        SET(p_strstream_buffer_ctor, "??0strstream@@QEAA@PEADHH@Z");
+        SET(p_strstream_ctor, "??0strstream@@QEAA@XZ");
+        SET(p_strstream_dtor, "??1strstream@@UEAA@XZ");
+        SET(p_strstream_vbase_dtor, "??_Dstrstream@@QEAAXXZ");
+        SET(p_strstream_assign, "??4strstream@@QEAAAEAV0@AEAV0@@Z");
+
         SET(p_Iostream_init_ios_ctor, "??0Iostream_init@@QEAA@AEAVios@@H@Z");
     } else {
         p_operator_new = (void*)GetProcAddress(msvcrt, "??2@YAPAXI@Z");
@@ -875,6 +890,13 @@ static BOOL init(void)
         SET(p_iostream_assign_sb, "??4iostream@@IAEAAV0@PAVstreambuf@@@Z");
         SET(p_iostream_assign, "??4iostream@@IAEAAV0@AAV0@@Z");
 
+        SET(p_strstream_copy_ctor, "??0strstream@@QAE@ABV0@@Z");
+        SET(p_strstream_buffer_ctor, "??0strstream@@QAE@PADHH@Z");
+        SET(p_strstream_ctor, "??0strstream@@QAE@XZ");
+        SET(p_strstream_dtor, "??1strstream@@UAE@XZ");
+        SET(p_strstream_vbase_dtor, "??_Dstrstream@@QAEXXZ");
+        SET(p_strstream_assign, "??4strstream@@QAEAAV0@AAV0@@Z");
+
         SET(p_Iostream_init_ios_ctor, "??0Iostream_init@@QAE@AAVios@@H@Z");
     }
     SET(p_ios_static_lock, "?x_lockc@ios@@0U_CRT_CRITICAL_SECTION@@A");
@@ -6658,6 +6680,339 @@ static void test_iostream(void)
     ok(ios2.base_ios.do_lock == 0xcdcdcdcd, "expected %d got %d\n", 0xcdcdcdcd, ios2.base_ios.do_lock);
 }
 
+static void test_strstream(void)
+{
+    iostream ios1, ios2, *pios;
+    ostream *pos;
+    strstreambuf *pssb;
+    char buffer[32];
+
+    memset(&ios1, 0xab, sizeof(iostream));
+    memset(&ios2, 0xab, sizeof(iostream));
+
+    /* constructors/destructors */
+    pios = call_func2(p_strstream_ctor, &ios1, TRUE);
+    pssb = (strstreambuf*) ios1.base_ios.sb;
+    ok(pios == &ios1, "wrong return, expected %p got %p\n", &ios1, pios);
+    ok(ios1.base1.extract_delim == 0, "expected 0 got %d\n", ios1.base1.extract_delim);
+    ok(ios1.base1.count == 0, "expected 0 got %d\n", ios1.base1.count);
+    ok(ios1.base2.unknown == 0, "expected 0 got %d\n", ios1.base2.unknown);
+    ok(ios1.base_ios.sb != NULL, "expected not %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == IOSTATE_goodbit, "expected %d got %d\n", IOSTATE_goodbit, ios1.base_ios.state);
+    ok(ios1.base_ios.delbuf == 1, "expected 1 got %d\n", ios1.base_ios.delbuf);
+    ok(ios1.base_ios.tie == NULL, "expected %p got %p\n", NULL, ios1.base_ios.tie);
+    ok(ios1.base_ios.flags == FLAGS_skipws, "expected %x got %x\n", FLAGS_skipws, ios1.base_ios.flags);
+    ok(ios1.base_ios.precision == 6, "expected 6 got %d\n", ios1.base_ios.precision);
+    ok(ios1.base_ios.fill == ' ', "expected 32 got %d\n", ios1.base_ios.fill);
+    ok(ios1.base_ios.width == 0, "expected 0 got %d\n", ios1.base_ios.width);
+    ok(ios1.base_ios.do_lock == -1, "expected -1 got %d\n", ios1.base_ios.do_lock);
+    ok(pssb->dynamic == 1, "expected 1, got %d\n", pssb->dynamic);
+    ok(pssb->increase == 1, "expected 1, got %d\n", pssb->increase);
+    ok(pssb->constant == 0, "expected 0, got %d\n", pssb->constant);
+    ok(pssb->f_alloc == NULL, "expected %p, got %p\n", NULL, pssb->f_alloc);
+    ok(pssb->f_free == NULL, "expected %p, got %p\n", NULL, pssb->f_free);
+    ok(pssb->base.allocated == 0, "wrong allocate value, expected 0 got %d\n", pssb->base.allocated);
+    ok(pssb->base.unbuffered == 0, "wrong unbuffered value, expected 0 got %d\n", pssb->base.unbuffered);
+    ok(pssb->base.base == NULL, "wrong buffer, expected %p got %p\n", NULL, pssb->base.base);
+    ok(pssb->base.ebuf == NULL, "wrong buffer end, expected %p got %p\n", NULL, pssb->base.ebuf);
+    ok(pssb->base.do_lock == -1, "expected -1 got %d\n", pssb->base.do_lock);
+    call_func1(p_strstream_vbase_dtor, &ios1);
+    ok(ios1.base_ios.sb == NULL, "expected %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == IOSTATE_badbit, "expected %d got %d\n", IOSTATE_badbit, ios1.base_ios.state);
+    ios1.base1.extract_delim = ios1.base1.count = 0xabababab;
+    ios1.base2.unknown = 0xabababab;
+    memset(&ios1.base_ios, 0xab, sizeof(ios));
+    ios1.base_ios.delbuf = 0;
+    pios = call_func2(p_strstream_ctor, &ios1, FALSE);
+    pssb = (strstreambuf*) ios1.base_ios.sb;
+    ok(pios == &ios1, "wrong return, expected %p got %p\n", &ios1, pios);
+    ok(ios1.base1.extract_delim == 0, "expected 0 got %d\n", ios1.base1.extract_delim);
+    ok(ios1.base1.count == 0, "expected 0 got %d\n", ios1.base1.count);
+    ok(ios1.base2.unknown == 0, "expected 0 got %d\n", ios1.base2.unknown);
+    ok(ios1.base_ios.sb != NULL, "expected not %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == 0xabababab, "expected %d got %d\n", 0xabababab, ios1.base_ios.state);
+    ok(ios1.base_ios.delbuf == 1, "expected 1 got %d\n", ios1.base_ios.delbuf);
+    ok(ios1.base_ios.tie == ios2.base_ios.tie, "expected %p got %p\n", ios2.base_ios.tie, ios1.base_ios.tie);
+    ok(ios1.base_ios.flags == 0xabababab, "expected %x got %x\n", 0xabababab, ios1.base_ios.flags);
+    ok(ios1.base_ios.precision == 0xabababab, "expected %d got %d\n", 0xabababab, ios1.base_ios.precision);
+    ok(ios1.base_ios.fill == (char) 0xab, "expected -85 got %d\n", ios1.base_ios.fill);
+    ok(ios1.base_ios.width == 0xabababab, "expected %d got %d\n", 0xabababab, ios1.base_ios.width);
+    ok(ios1.base_ios.do_lock == 0xabababab, "expected %d got %d\n", 0xabababab, ios1.base_ios.do_lock);
+    ok(pssb->dynamic == 1, "expected 1, got %d\n", pssb->dynamic);
+    ok(pssb->increase == 1, "expected 1, got %d\n", pssb->increase);
+    ok(pssb->constant == 0, "expected 0, got %d\n", pssb->constant);
+    ok(pssb->f_alloc == NULL, "expected %p, got %p\n", NULL, pssb->f_alloc);
+    ok(pssb->f_free == NULL, "expected %p, got %p\n", NULL, pssb->f_free);
+    ok(pssb->base.allocated == 0, "wrong allocate value, expected 0 got %d\n", pssb->base.allocated);
+    ok(pssb->base.unbuffered == 0, "wrong unbuffered value, expected 0 got %d\n", pssb->base.unbuffered);
+    ok(pssb->base.base == NULL, "wrong buffer, expected %p got %p\n", NULL, pssb->base.base);
+    ok(pssb->base.ebuf == NULL, "wrong buffer end, expected %p got %p\n", NULL, pssb->base.ebuf);
+    ok(pssb->base.do_lock == -1, "expected -1 got %d\n", pssb->base.do_lock);
+    call_func1(p_strstream_dtor, &ios1.base_ios);
+    ok(ios1.base_ios.sb == &pssb->base, "expected %p got %p\n", &pssb->base, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == 0xabababab, "expected %d got %d\n", 0xabababab, ios1.base_ios.state);
+    call_func1(p_strstreambuf_dtor, pssb);
+    p_operator_delete(pssb);
+
+    memset(&ios1, 0xab, sizeof(iostream));
+    pios = call_func5(p_strstream_buffer_ctor, &ios1, buffer, 32, 0, TRUE);
+    pssb = (strstreambuf*) ios1.base_ios.sb;
+    ok(pios == &ios1, "wrong return, expected %p got %p\n", &ios1, pios);
+    ok(ios1.base1.extract_delim == 0, "expected 0 got %d\n", ios1.base1.extract_delim);
+    ok(ios1.base1.count == 0, "expected 0 got %d\n", ios1.base1.count);
+    ok(ios1.base2.unknown == 0, "expected 0 got %d\n", ios1.base2.unknown);
+    ok(ios1.base_ios.sb != NULL, "expected not %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == IOSTATE_goodbit, "expected %d got %d\n", IOSTATE_goodbit, ios1.base_ios.state);
+    ok(ios1.base_ios.delbuf == 1, "expected 1 got %d\n", ios1.base_ios.delbuf);
+    ok(ios1.base_ios.tie == NULL, "expected %p got %p\n", NULL, ios1.base_ios.tie);
+    ok(ios1.base_ios.flags == FLAGS_skipws, "expected %x got %x\n", FLAGS_skipws, ios1.base_ios.flags);
+    ok(ios1.base_ios.precision == 6, "expected 6 got %d\n", ios1.base_ios.precision);
+    ok(ios1.base_ios.fill == ' ', "expected 32 got %d\n", ios1.base_ios.fill);
+    ok(ios1.base_ios.width == 0, "expected 0 got %d\n", ios1.base_ios.width);
+    ok(ios1.base_ios.do_lock == -1, "expected -1 got %d\n", ios1.base_ios.do_lock);
+    ok(pssb->dynamic == 0, "expected 0, got %d\n", pssb->dynamic);
+    ok(pssb->constant == 1, "expected 1, got %d\n", pssb->constant);
+    ok(pssb->base.allocated == 0, "wrong allocate value, expected 0 got %d\n", pssb->base.allocated);
+    ok(pssb->base.unbuffered == 0, "wrong unbuffered value, expected 0 got %d\n", pssb->base.unbuffered);
+    ok(pssb->base.base == buffer, "wrong buffer, expected %p got %p\n", buffer, pssb->base.base);
+    ok(pssb->base.ebuf == buffer + 32, "wrong buffer end, expected %p got %p\n", buffer + 32, pssb->base.ebuf);
+    ok(pssb->base.eback == buffer, "wrong get base, expected %p got %p\n", buffer, pssb->base.eback);
+    ok(pssb->base.gptr == buffer, "wrong get pointer, expected %p got %p\n", buffer, pssb->base.gptr);
+    ok(pssb->base.egptr == buffer, "wrong get end, expected %p got %p\n", buffer, pssb->base.egptr);
+    ok(pssb->base.pbase == buffer, "wrong put base, expected %p got %p\n", buffer, pssb->base.pbase);
+    ok(pssb->base.pptr == buffer, "wrong put pointer, expected %p got %p\n", buffer, pssb->base.pptr);
+    ok(pssb->base.epptr == buffer + 32, "wrong put end, expected %p got %p\n", buffer + 32, pssb->base.epptr);
+    ok(pssb->base.do_lock == -1, "expected -1 got %d\n", pssb->base.do_lock);
+    call_func1(p_strstream_vbase_dtor, &ios1);
+    ok(ios1.base_ios.sb == NULL, "expected %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == IOSTATE_badbit, "expected %d got %d\n", IOSTATE_badbit, ios1.base_ios.state);
+    memset(&ios1, 0xab, sizeof(iostream));
+    pios = call_func5(p_strstream_buffer_ctor, &ios1, buffer, 16, OPENMODE_in, TRUE);
+    pssb = (strstreambuf*) ios1.base_ios.sb;
+    ok(pios == &ios1, "wrong return, expected %p got %p\n", &ios1, pios);
+    ok(ios1.base1.extract_delim == 0, "expected 0 got %d\n", ios1.base1.extract_delim);
+    ok(ios1.base1.count == 0, "expected 0 got %d\n", ios1.base1.count);
+    ok(ios1.base2.unknown == 0, "expected 0 got %d\n", ios1.base2.unknown);
+    ok(ios1.base_ios.sb != NULL, "expected not %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == IOSTATE_goodbit, "expected %d got %d\n", IOSTATE_goodbit, ios1.base_ios.state);
+    ok(ios1.base_ios.delbuf == 1, "expected 1 got %d\n", ios1.base_ios.delbuf);
+    ok(ios1.base_ios.tie == NULL, "expected %p got %p\n", NULL, ios1.base_ios.tie);
+    ok(ios1.base_ios.flags == FLAGS_skipws, "expected %x got %x\n", FLAGS_skipws, ios1.base_ios.flags);
+    ok(ios1.base_ios.precision == 6, "expected 6 got %d\n", ios1.base_ios.precision);
+    ok(ios1.base_ios.fill == ' ', "expected 32 got %d\n", ios1.base_ios.fill);
+    ok(ios1.base_ios.width == 0, "expected 0 got %d\n", ios1.base_ios.width);
+    ok(ios1.base_ios.do_lock == -1, "expected -1 got %d\n", ios1.base_ios.do_lock);
+    ok(pssb->dynamic == 0, "expected 0, got %d\n", pssb->dynamic);
+    ok(pssb->constant == 1, "expected 1, got %d\n", pssb->constant);
+    ok(pssb->base.allocated == 0, "wrong allocate value, expected 0 got %d\n", pssb->base.allocated);
+    ok(pssb->base.unbuffered == 0, "wrong unbuffered value, expected 0 got %d\n", pssb->base.unbuffered);
+    ok(pssb->base.base == buffer, "wrong buffer, expected %p got %p\n", buffer, pssb->base.base);
+    ok(pssb->base.ebuf == buffer + 16, "wrong buffer end, expected %p got %p\n", buffer + 16, pssb->base.ebuf);
+    ok(pssb->base.eback == buffer, "wrong get base, expected %p got %p\n", buffer, pssb->base.eback);
+    ok(pssb->base.gptr == buffer, "wrong get pointer, expected %p got %p\n", buffer, pssb->base.gptr);
+    ok(pssb->base.egptr == buffer, "wrong get end, expected %p got %p\n", buffer, pssb->base.egptr);
+    ok(pssb->base.pbase == buffer, "wrong put base, expected %p got %p\n", buffer, pssb->base.pbase);
+    ok(pssb->base.pptr == buffer, "wrong put pointer, expected %p got %p\n", buffer, pssb->base.pptr);
+    ok(pssb->base.epptr == buffer + 16, "wrong put end, expected %p got %p\n", buffer + 16, pssb->base.epptr);
+    ok(pssb->base.do_lock == -1, "expected -1 got %d\n", pssb->base.do_lock);
+    call_func1(p_strstream_vbase_dtor, &ios1);
+    ok(ios1.base_ios.sb == NULL, "expected %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == IOSTATE_badbit, "expected %d got %d\n", IOSTATE_badbit, ios1.base_ios.state);
+    memset(&ios1, 0xab, sizeof(iostream));
+    pios = call_func5(p_strstream_buffer_ctor, &ios1, buffer, -1, OPENMODE_in|OPENMODE_out, TRUE);
+    pssb = (strstreambuf*) ios1.base_ios.sb;
+    ok(pios == &ios1, "wrong return, expected %p got %p\n", &ios1, pios);
+    ok(ios1.base1.extract_delim == 0, "expected 0 got %d\n", ios1.base1.extract_delim);
+    ok(ios1.base1.count == 0, "expected 0 got %d\n", ios1.base1.count);
+    ok(ios1.base2.unknown == 0, "expected 0 got %d\n", ios1.base2.unknown);
+    ok(ios1.base_ios.sb != NULL, "expected not %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == IOSTATE_goodbit, "expected %d got %d\n", IOSTATE_goodbit, ios1.base_ios.state);
+    ok(ios1.base_ios.delbuf == 1, "expected 1 got %d\n", ios1.base_ios.delbuf);
+    ok(ios1.base_ios.tie == NULL, "expected %p got %p\n", NULL, ios1.base_ios.tie);
+    ok(ios1.base_ios.flags == FLAGS_skipws, "expected %x got %x\n", FLAGS_skipws, ios1.base_ios.flags);
+    ok(ios1.base_ios.precision == 6, "expected 6 got %d\n", ios1.base_ios.precision);
+    ok(ios1.base_ios.fill == ' ', "expected 32 got %d\n", ios1.base_ios.fill);
+    ok(ios1.base_ios.width == 0, "expected 0 got %d\n", ios1.base_ios.width);
+    ok(ios1.base_ios.do_lock == -1, "expected -1 got %d\n", ios1.base_ios.do_lock);
+    ok(pssb->dynamic == 0, "expected 0, got %d\n", pssb->dynamic);
+    ok(pssb->constant == 1, "expected 1, got %d\n", pssb->constant);
+    ok(pssb->base.allocated == 0, "wrong allocate value, expected 0 got %d\n", pssb->base.allocated);
+    ok(pssb->base.unbuffered == 0, "wrong unbuffered value, expected 0 got %d\n", pssb->base.unbuffered);
+    ok(pssb->base.base == buffer, "wrong buffer, expected %p got %p\n", buffer, pssb->base.base);
+    ok(pssb->base.ebuf == buffer + 0x7fffffff || pssb->base.ebuf == (char*) -1,
+        "wrong buffer end, expected %p + 0x7fffffff or -1, got %p\n", buffer, pssb->base.ebuf);
+    ok(pssb->base.eback == buffer, "wrong get base, expected %p got %p\n", buffer, pssb->base.eback);
+    ok(pssb->base.gptr == buffer, "wrong get pointer, expected %p got %p\n", buffer, pssb->base.gptr);
+    ok(pssb->base.egptr == buffer, "wrong get end, expected %p got %p\n", buffer, pssb->base.egptr);
+    ok(pssb->base.pbase == buffer, "wrong put base, expected %p got %p\n", buffer, pssb->base.pbase);
+    ok(pssb->base.pptr == buffer, "wrong put pointer, expected %p got %p\n", buffer, pssb->base.pptr);
+    ok(pssb->base.epptr == buffer + 0x7fffffff || pssb->base.epptr == (char*) -1,
+        "wrong buffer end, expected %p + 0x7fffffff or -1, got %p\n", buffer, pssb->base.epptr);
+    ok(pssb->base.do_lock == -1, "expected -1 got %d\n", pssb->base.do_lock);
+    call_func1(p_strstream_vbase_dtor, &ios1);
+    ok(ios1.base_ios.sb == NULL, "expected %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == IOSTATE_badbit, "expected %d got %d\n", IOSTATE_badbit, ios1.base_ios.state);
+    ios1.base1.extract_delim = ios1.base1.count = 0xabababab;
+    ios1.base2.unknown = 0xabababab;
+    memset(&ios1.base_ios, 0xab, sizeof(ios));
+    ios1.base_ios.delbuf = 0;
+    strcpy(buffer, "Test");
+    pios = call_func5(p_strstream_buffer_ctor, &ios1, buffer, 0, OPENMODE_in|OPENMODE_app, FALSE);
+    pssb = (strstreambuf*) ios1.base_ios.sb;
+    ok(pios == &ios1, "wrong return, expected %p got %p\n", &ios1, pios);
+    ok(ios1.base1.extract_delim == 0, "expected 0 got %d\n", ios1.base1.extract_delim);
+    ok(ios1.base1.count == 0, "expected 0 got %d\n", ios1.base1.count);
+    ok(ios1.base2.unknown == 0, "expected 0 got %d\n", ios1.base2.unknown);
+    ok(ios1.base_ios.sb != NULL, "expected not %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == 0xabababab, "expected %d got %d\n", 0xabababab, ios1.base_ios.state);
+    ok(ios1.base_ios.delbuf == 1, "expected 1 got %d\n", ios1.base_ios.delbuf);
+    ok(ios1.base_ios.tie == ios2.base_ios.tie, "expected %p got %p\n", ios2.base_ios.tie, ios1.base_ios.tie);
+    ok(ios1.base_ios.flags == 0xabababab, "expected %x got %x\n", 0xabababab, ios1.base_ios.flags);
+    ok(ios1.base_ios.precision == 0xabababab, "expected %d got %d\n", 0xabababab, ios1.base_ios.precision);
+    ok(ios1.base_ios.fill == (char) 0xab, "expected -85 got %d\n", ios1.base_ios.fill);
+    ok(ios1.base_ios.width == 0xabababab, "expected %d got %d\n", 0xabababab, ios1.base_ios.width);
+    ok(ios1.base_ios.do_lock == 0xabababab, "expected %d got %d\n", 0xabababab, ios1.base_ios.do_lock);
+    ok(pssb->dynamic == 0, "expected 0, got %d\n", pssb->dynamic);
+    ok(pssb->constant == 1, "expected 1, got %d\n", pssb->constant);
+    ok(pssb->base.allocated == 0, "wrong allocate value, expected 0 got %d\n", pssb->base.allocated);
+    ok(pssb->base.unbuffered == 0, "wrong unbuffered value, expected 0 got %d\n", pssb->base.unbuffered);
+    ok(pssb->base.base == buffer, "wrong buffer, expected %p got %p\n", buffer, pssb->base.base);
+    ok(pssb->base.ebuf == buffer + 4, "wrong buffer end, expected %p got %p\n", buffer + 4, pssb->base.ebuf);
+    ok(pssb->base.eback == buffer, "wrong get base, expected %p got %p\n", buffer, pssb->base.eback);
+    ok(pssb->base.gptr == buffer, "wrong get pointer, expected %p got %p\n", buffer, pssb->base.gptr);
+    ok(pssb->base.egptr == buffer, "wrong get end, expected %p got %p\n", buffer, pssb->base.egptr);
+    ok(pssb->base.pbase == buffer, "wrong put base, expected %p got %p\n", buffer, pssb->base.pbase);
+    ok(pssb->base.pptr == buffer, "wrong put pointer, expected %p got %p\n", buffer, pssb->base.pptr);
+    ok(pssb->base.epptr == buffer + 4, "wrong put end, expected %p got %p\n", buffer + 4, pssb->base.epptr);
+    ok(pssb->base.do_lock == -1, "expected -1 got %d\n", pssb->base.do_lock);
+    call_func1(p_strstream_dtor, &ios1.base_ios);
+    ok(ios1.base_ios.sb == &pssb->base, "expected %p got %p\n", &pssb->base, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == 0xabababab, "expected %d got %d\n", 0xabababab, ios1.base_ios.state);
+    call_func1(p_strstreambuf_dtor, pssb);
+    p_operator_delete(pssb);
+    memset(&ios1, 0xab, sizeof(iostream));
+    pios = call_func5(p_strstream_buffer_ctor, &ios1, buffer, 16, OPENMODE_ate, TRUE);
+    pssb = (strstreambuf*) ios1.base_ios.sb;
+    ok(pios == &ios1, "wrong return, expected %p got %p\n", &ios1, pios);
+    ok(ios1.base1.extract_delim == 0, "expected 0 got %d\n", ios1.base1.extract_delim);
+    ok(ios1.base1.count == 0, "expected 0 got %d\n", ios1.base1.count);
+    ok(ios1.base2.unknown == 0, "expected 0 got %d\n", ios1.base2.unknown);
+    ok(ios1.base_ios.sb != NULL, "expected not %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == IOSTATE_goodbit, "expected %d got %d\n", IOSTATE_goodbit, ios1.base_ios.state);
+    ok(ios1.base_ios.delbuf == 1, "expected 1 got %d\n", ios1.base_ios.delbuf);
+    ok(ios1.base_ios.tie == NULL, "expected %p got %p\n", NULL, ios1.base_ios.tie);
+    ok(ios1.base_ios.flags == FLAGS_skipws, "expected %x got %x\n", FLAGS_skipws, ios1.base_ios.flags);
+    ok(ios1.base_ios.precision == 6, "expected 6 got %d\n", ios1.base_ios.precision);
+    ok(ios1.base_ios.fill == ' ', "expected 32 got %d\n", ios1.base_ios.fill);
+    ok(ios1.base_ios.width == 0, "expected 0 got %d\n", ios1.base_ios.width);
+    ok(ios1.base_ios.do_lock == -1, "expected -1 got %d\n", ios1.base_ios.do_lock);
+    ok(pssb->dynamic == 0, "expected 0, got %d\n", pssb->dynamic);
+    ok(pssb->constant == 1, "expected 1, got %d\n", pssb->constant);
+    ok(pssb->base.allocated == 0, "wrong allocate value, expected 0 got %d\n", pssb->base.allocated);
+    ok(pssb->base.unbuffered == 0, "wrong unbuffered value, expected 0 got %d\n", pssb->base.unbuffered);
+    ok(pssb->base.base == buffer, "wrong buffer, expected %p got %p\n", buffer, pssb->base.base);
+    ok(pssb->base.ebuf == buffer + 16, "wrong buffer end, expected %p got %p\n", buffer + 16, pssb->base.ebuf);
+    ok(pssb->base.eback == buffer, "wrong get base, expected %p got %p\n", buffer, pssb->base.eback);
+    ok(pssb->base.gptr == buffer, "wrong get pointer, expected %p got %p\n", buffer, pssb->base.gptr);
+    ok(pssb->base.egptr == buffer, "wrong get end, expected %p got %p\n", buffer, pssb->base.egptr);
+    ok(pssb->base.pbase == buffer, "wrong put base, expected %p got %p\n", buffer, pssb->base.pbase);
+    ok(pssb->base.pptr == buffer, "wrong put pointer, expected %p got %p\n", buffer, pssb->base.pptr);
+    ok(pssb->base.epptr == buffer + 16, "wrong put end, expected %p got %p\n", buffer + 16, pssb->base.epptr);
+    ok(pssb->base.do_lock == -1, "expected -1 got %d\n", pssb->base.do_lock);
+    call_func1(p_strstream_vbase_dtor, &ios1);
+    ok(ios1.base_ios.sb == NULL, "expected %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == IOSTATE_badbit, "expected %d got %d\n", IOSTATE_badbit, ios1.base_ios.state);
+    pios = call_func5(p_strstream_buffer_ctor, &ios1, buffer, 16, OPENMODE_out|OPENMODE_ate, TRUE);
+    pssb = (strstreambuf*) ios1.base_ios.sb;
+    ok(pios == &ios1, "wrong return, expected %p got %p\n", &ios1, pios);
+    ok(ios1.base1.extract_delim == 0, "expected 0 got %d\n", ios1.base1.extract_delim);
+    ok(ios1.base1.count == 0, "expected 0 got %d\n", ios1.base1.count);
+    ok(ios1.base2.unknown == 0, "expected 0 got %d\n", ios1.base2.unknown);
+    ok(ios1.base_ios.sb != NULL, "expected not %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == IOSTATE_goodbit, "expected %d got %d\n", IOSTATE_goodbit, ios1.base_ios.state);
+    ok(ios1.base_ios.delbuf == 1, "expected 1 got %d\n", ios1.base_ios.delbuf);
+    ok(ios1.base_ios.tie == NULL, "expected %p got %p\n", NULL, ios1.base_ios.tie);
+    ok(ios1.base_ios.flags == FLAGS_skipws, "expected %x got %x\n", FLAGS_skipws, ios1.base_ios.flags);
+    ok(ios1.base_ios.precision == 6, "expected 6 got %d\n", ios1.base_ios.precision);
+    ok(ios1.base_ios.fill == ' ', "expected 32 got %d\n", ios1.base_ios.fill);
+    ok(ios1.base_ios.width == 0, "expected 0 got %d\n", ios1.base_ios.width);
+    ok(ios1.base_ios.do_lock == -1, "expected -1 got %d\n", ios1.base_ios.do_lock);
+    ok(pssb->dynamic == 0, "expected 0, got %d\n", pssb->dynamic);
+    ok(pssb->constant == 1, "expected 1, got %d\n", pssb->constant);
+    ok(pssb->base.allocated == 0, "wrong allocate value, expected 0 got %d\n", pssb->base.allocated);
+    ok(pssb->base.unbuffered == 0, "wrong unbuffered value, expected 0 got %d\n", pssb->base.unbuffered);
+    ok(pssb->base.base == buffer, "wrong buffer, expected %p got %p\n", buffer, pssb->base.base);
+    ok(pssb->base.ebuf == buffer + 16, "wrong buffer end, expected %p got %p\n", buffer + 16, pssb->base.ebuf);
+    ok(pssb->base.eback == buffer, "wrong get base, expected %p got %p\n", buffer, pssb->base.eback);
+    ok(pssb->base.gptr == buffer, "wrong get pointer, expected %p got %p\n", buffer, pssb->base.gptr);
+    ok(pssb->base.egptr == buffer, "wrong get end, expected %p got %p\n", buffer, pssb->base.egptr);
+    ok(pssb->base.pbase == buffer, "wrong put base, expected %p got %p\n", buffer, pssb->base.pbase);
+    ok(pssb->base.pptr == buffer + 4, "wrong put pointer, expected %p got %p\n", buffer + 4, pssb->base.pptr);
+    ok(pssb->base.epptr == buffer + 16, "wrong put end, expected %p got %p\n", buffer + 16, pssb->base.epptr);
+    ok(pssb->base.do_lock == -1, "expected -1 got %d\n", pssb->base.do_lock);
+    call_func1(p_strstream_vbase_dtor, &ios1);
+    ok(ios1.base_ios.sb == NULL, "expected %p got %p\n", NULL, ios1.base_ios.sb);
+    ok(ios1.base_ios.state == IOSTATE_badbit, "expected %d got %d\n", IOSTATE_badbit, ios1.base_ios.state);
+
+    ios1.base1.extract_delim = ios1.base1.count = 0xcdcdcdcd;
+    ios1.base2.unknown = 0xcdcdcdcd;
+    memset(&ios1.base_ios, 0xcd, sizeof(ios));
+    pios = call_func3(p_strstream_copy_ctor, &ios2, &ios1, TRUE);
+    ok(pios == &ios2, "wrong return, expected %p got %p\n", &ios2, pios);
+    ok(ios2.base1.extract_delim == 0, "expected 0 got %d\n", ios2.base1.extract_delim);
+    ok(ios2.base1.count == 0, "expected 0 got %d\n", ios2.base1.count);
+    ok(ios2.base2.unknown == 0, "expected 0 got %d\n", ios2.base2.unknown);
+    ok(ios2.base_ios.sb == ios1.base_ios.sb, "expected %p got %p\n", ios1.base_ios.sb, ios2.base_ios.sb);
+    ok(ios2.base_ios.state == 0xcdcdcdc9, "expected %d got %d\n", 0xcdcdcdc9, ios2.base_ios.state);
+    ok(ios2.base_ios.delbuf == 0, "expected 0 got %d\n", ios2.base_ios.delbuf);
+    ok(ios2.base_ios.tie == ios1.base_ios.tie, "expected %p got %p\n", ios1.base_ios.tie, ios2.base_ios.tie);
+    ok(ios2.base_ios.flags == 0xcdcdcdcd, "expected %x got %x\n", 0xcdcdcdcd, ios2.base_ios.flags);
+    ok(ios2.base_ios.precision == (char) 0xcd, "expected -51 got %d\n", ios2.base_ios.precision);
+    ok(ios2.base_ios.fill == (char) 0xcd, "expected -51 got %d\n", ios2.base_ios.fill);
+    ok(ios2.base_ios.width == (char) 0xcd, "expected -51 got %d\n", ios2.base_ios.width);
+    ok(ios2.base_ios.do_lock == -1, "expected -1 got %d\n", ios2.base_ios.do_lock);
+    call_func1(p_strstream_vbase_dtor, &ios2);
+    ios2.base1.extract_delim = ios2.base1.count = 0xabababab;
+    ios2.base2.unknown = 0xabababab;
+    memset(&ios2.base_ios, 0xab, sizeof(ios));
+    ios2.base_ios.delbuf = 0;
+    pos = ios2.base_ios.tie;
+    pios = call_func3(p_strstream_copy_ctor, &ios2, &ios1, FALSE);
+    ok(pios == &ios2, "wrong return, expected %p got %p\n", &ios2, pios);
+    ok(ios2.base1.extract_delim == 0, "expected 0 got %d\n", ios2.base1.extract_delim);
+    ok(ios2.base1.count == 0, "expected 0 got %d\n", ios2.base1.count);
+    ok(ios2.base2.unknown == 0, "expected 0 got %d\n", ios2.base2.unknown);
+    ok(ios2.base_ios.sb == ios1.base_ios.sb, "expected %p got %p\n", ios1.base_ios.sb, ios2.base_ios.sb);
+    ok(ios2.base_ios.state == 0xabababab, "expected %d got %d\n", 0xabababab, ios2.base_ios.state);
+    ok(ios2.base_ios.delbuf == 0, "expected 0 got %d\n", ios2.base_ios.delbuf);
+    ok(ios2.base_ios.tie == pos, "expected %p got %p\n", pos, ios2.base_ios.tie);
+    ok(ios2.base_ios.flags == 0xabababab, "expected %x got %x\n", 0xabababab, ios2.base_ios.flags);
+    ok(ios2.base_ios.precision == 0xabababab, "expected %d got %d\n", 0xabababab, ios2.base_ios.precision);
+    ok(ios2.base_ios.fill == (char) 0xab, "expected -85 got %d\n", ios2.base_ios.fill);
+    ok(ios2.base_ios.width == 0xabababab, "expected %d got %d\n", 0xabababab, ios2.base_ios.width);
+    ok(ios2.base_ios.do_lock == 0xabababab, "expected %d got %d\n", 0xabababab, ios2.base_ios.do_lock);
+    call_func1(p_strstream_dtor, &ios2.base_ios);
+
+    /* assignment */
+    ios2.base1.extract_delim = ios2.base1.count = 0xabababab;
+    ios2.base2.unknown = 0xabababab;
+    memset(&ios2.base_ios, 0xab, sizeof(ios));
+    ios2.base_ios.delbuf = 0;
+    pios = call_func2(p_strstream_assign, &ios2, &ios1);
+    ok(ios2.base1.extract_delim == 0xabababab, "expected %d got %d\n", 0xabababab, ios2.base1.extract_delim);
+    ok(ios2.base1.count == 0, "expected 0 got %d\n", ios2.base1.count);
+    ok(ios2.base2.unknown == 0xabababab, "expected %d got %d\n", 0xabababab, ios2.base2.unknown);
+    ok(ios2.base_ios.sb == ios1.base_ios.sb, "expected %p got %p\n", ios1.base_ios.sb, ios2.base_ios.sb);
+    ok(ios2.base_ios.state == IOSTATE_goodbit, "expected %d got %d\n", IOSTATE_goodbit, ios2.base_ios.state);
+    ok(ios2.base_ios.delbuf == 0, "expected 0 got %d\n", ios2.base_ios.delbuf);
+    ok(ios2.base_ios.tie == NULL, "expected %p got %p\n", NULL, ios2.base_ios.tie);
+    ok(ios2.base_ios.flags == 0, "expected 0 got %x\n", ios2.base_ios.flags);
+    ok(ios2.base_ios.precision == 6, "expected 6 got %d\n", ios2.base_ios.precision);
+    ok(ios2.base_ios.fill == ' ', "expected 32 got %d\n", ios2.base_ios.fill);
+    ok(ios2.base_ios.width == 0, "expected 0 got %d\n", ios2.base_ios.width);
+    ok(ios2.base_ios.do_lock == 0xabababab, "expected %d got %d\n", 0xabababab, ios2.base_ios.do_lock);
+}
+
 static void test_Iostream_init(void)
 {
     ios ios_obj;
@@ -6954,6 +7309,7 @@ START_TEST(msvcirt)
     test_istream_withassign();
     test_istrstream();
     test_iostream();
+    test_strstream();
     test_Iostream_init();
     test_std_streams();